FA-75361 / Text diff and three-way merge / Open access
Myers greedy edit distance: the furthest-reaching predecessor comparison is inverted · case 01
Reported distances are larger than the true minimum.
ROOT CAUSE
The choice between moving down from k+1 and right from k-1 prefers the shorter path.
VERIFIED REPAIR
Move down from k+1 when V[k-1] < V[k+1], otherwise right from k-1.
Unsuccessful approach: Only special-casing the k == -d edge always moves right and misses better paths from k+1.
Case contract
Compute the minimum number of line insertions plus deletions between a and b using the greedy furthest-reaching diagonal method: for d = 0..min(max_d, n+m), for k = -d..d step 2 choose the start x from diagonal k+1 when k == -d or (k != d and V[k-1] < V[k+1]), else V[k-1]+1; follow the snake of equal elements; return d once x >= n and y >= m. Return None when the distance exceeds max_d.
Why this case matters
Diff engines use Myers' O(ND) algorithm with a cap on D to bound work on very different files.
1 / The failure
Exit 1"""Failure Map reference implementation. Python standard library only."""
import json
N = 1
observations = []
def solve(a, b, max_d):
n, m = len(a), len(b)
off = n + m + 1
v = [0] * (2 * off + 2)
for d in range(0, min(max_d, n + m) + 1):
for k in range(-d, d + 1, 2):
if k == -d or (k != d and v[off + k - 1] > v[off + k + 1]):
x = v[off + k + 1]
else:
x = v[off + k - 1] + 1
y = x - k
while x < n and y < m and a[x] == b[y]:
x += 1
y += 1
v[off + k] = x
if x >= n and y >= m:
return d
return None
def check(label, actual, expected):
observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
cases = {
1: [('classic example', [['a', 'b', 'c', 'a', 'b', 'b', 'a'], ['c', 'b', 'a', 'b', 'a', 'c'], 20], 5), ('identical', [['x'], ['x'], 5], 0), ('all different', [['a', 'b'], ['c', 'd'], 10], 4), ('cap equal to distance', [['a', 'b', 'c'], ['a', 'b', 'd'], 2], 2), ('cap below distance', [['a', 'b', 'c', 'd'], ['w', 'x', 'y', 'z'], 4], None), ('one side empty', [[], ['q'], 2], 1), ('insert in the middle', [['a', 'a', 'a', 'a'], ['a', 'a', 'b', 'a', 'a'], 4], 1), ('long snakes', [['a', 'b', 'c', 'd', 'e', 'f', 'g', 'h'], ['a', 'b', 'c', 'X', 'd', 'e', 'f', 'g'], 9], 2), ('distance exactly the total length', [['a', 'b'], ['c', 'd', 'e'], 5], 5), ('single edits scattered', [['a', 'b', 'c', 'd', 'e', 'f', 'g'], ['b', 'c', 'd', 'x', 'e', 'f', 'g', 'y'], 12], 3)],
2: [('classic example', [['a', 'b', 'c', 'a', 'b', 'b', 'a'], ['c', 'b', 'a', 'b', 'a', 'c'], 20], 5), ('identical', [['x', 'x'], ['x', 'x'], 5], 0), ('all different', [['a', 'b'], ['c', 'd'], 10], 4), ('cap equal to distance', [['a', 'b', 'c'], ['a', 'b', 'd'], 2], 2), ('cap below distance', [['a', 'b', 'c', 'd'], ['w', 'x', 'y', 'z'], 3], None), ('one side empty', [[], ['q', 'q'], 3], 2), ('insert in the middle', [['a', 'a', 'a', 'a'], ['a', 'a', 'b', 'a', 'a'], 4], 1), ('long snakes', [['a', 'b', 'c', 'd', 'e', 'f', 'g', 'h'], ['a', 'b', 'c', 'X', 'd', 'e', 'f', 'g', 'h'], 9], 1), ('distance exactly the total length', [['a', 'b'], ['c', 'd', 'e'], 5], 5), ('single edits scattered', [['a', 'b', 'c', 'd', 'e', 'f', 'g'], ['b', 'c', 'd', 'x', 'e', 'f', 'g', 'y'], 12], 3)],
3: [('classic example', [['a', 'b', 'c', 'a', 'b', 'b', 'a'], ['c', 'b', 'a', 'b', 'a', 'c'], 20], 5), ('identical', [['x', 'x', 'x'], ['x', 'x', 'x'], 5], 0), ('all different', [['a', 'b'], ['c', 'd'], 10], 4), ('cap equal to distance', [['a', 'b', 'c'], ['a', 'b', 'd'], 2], 2), ('cap below distance', [['a', 'b', 'c', 'd'], ['w', 'x', 'y', 'z'], 4], None), ('one side empty', [[], ['q', 'q', 'q'], 4], 3), ('insert in the middle', [['a', 'a', 'a', 'a'], ['a', 'a', 'b', 'a', 'a'], 4], 1), ('long snakes', [['a', 'b', 'c', 'd', 'e', 'f', 'g', 'h'], ['a', 'b', 'c', 'X', 'd', 'e', 'f', 'g'], 9], 2), ('distance exactly the total length', [['a', 'b'], ['c', 'd', 'e'], 5], 5), ('single edits scattered', [['a', 'b', 'c', 'd', 'e', 'f', 'g'], ['b', 'c', 'd', 'x', 'e', 'f', 'g', 'y'], 12], 3)],
4: [('classic example', [['a', 'b', 'c', 'a', 'b', 'b', 'a'], ['c', 'b', 'a', 'b', 'a', 'c'], 20], 5), ('identical', [['x', 'x', 'x', 'x'], ['x', 'x', 'x', 'x'], 5], 0), ('all different', [['a', 'b'], ['c', 'd'], 10], 4), ('cap equal to distance', [['a', 'b', 'c'], ['a', 'b', 'd'], 2], 2), ('cap below distance', [['a', 'b', 'c', 'd'], ['w', 'x', 'y', 'z'], 3], None), ('one side empty', [[], ['q', 'q', 'q', 'q'], 5], 4), ('insert in the middle', [['a', 'a', 'a', 'a'], ['a', 'a', 'b', 'a', 'a'], 4], 1), ('long snakes', [['a', 'b', 'c', 'd', 'e', 'f', 'g', 'h'], ['a', 'b', 'c', 'X', 'd', 'e', 'f', 'g', 'h'], 9], 1), ('distance exactly the total length', [['a', 'b'], ['c', 'd', 'e'], 5], 5), ('single edits scattered', [['a', 'b', 'c', 'd', 'e', 'f', 'g'], ['b', 'c', 'd', 'x', 'e', 'f', 'g', 'y'], 12], 3)],
5: [('classic example', [['a', 'b', 'c', 'a', 'b', 'b', 'a'], ['c', 'b', 'a', 'b', 'a', 'c'], 20], 5), ('identical', [['x', 'x', 'x', 'x', 'x'], ['x', 'x', 'x', 'x', 'x'], 5], 0), ('all different', [['a', 'b'], ['c', 'd'], 10], 4), ('cap equal to distance', [['a', 'b', 'c'], ['a', 'b', 'd'], 2], 2), ('cap below distance', [['a', 'b', 'c', 'd'], ['w', 'x', 'y', 'z'], 4], None), ('one side empty', [[], ['q', 'q', 'q', 'q', 'q'], 6], 5), ('insert in the middle', [['a', 'a', 'a', 'a'], ['a', 'a', 'b', 'a', 'a'], 4], 1), ('long snakes', [['a', 'b', 'c', 'd', 'e', 'f', 'g', 'h'], ['a', 'b', 'c', 'X', 'd', 'e', 'f', 'g'], 9], 2), ('distance exactly the total length', [['a', 'b'], ['c', 'd', 'e'], 5], 5), ('single edits scattered', [['a', 'b', 'c', 'd', 'e', 'f', 'g'], ['b', 'c', 'd', 'x', 'e', 'f', 'g', 'y'], 12], 3)],
}[N]
for label, args, expected in cases:
check(label, solve(*args), expected)
print(json.dumps({"observations": observations, "passed": all(x["passed"] for x in observations)}, ensure_ascii=False))
raise SystemExit(0 if all(x["passed"] for x in observations) else 1)
| Boundary fixture | Actual | Expected | Outcome |
|---|---|---|---|
| classic example | 7 | 5 | Failed |
| identical | 0 | 0 | Passed |
| all different | 4 | 4 | Passed |
| cap equal to distance | 2 | 2 | Passed |
| cap below distance | None | None | Passed |
| one side empty | 1 | 1 | Passed |
| insert in the middle | 1 | 1 | Passed |
| long snakes | 4 | 2 | Failed |
| distance exactly the total length | 5 | 5 | Passed |
| single edits scattered | None | 3 | Failed |
SHA-256 / f61a3db24b4105c18ec10e30d9cd64cdda307642f8658367baea71073d9fa23e
2 / The unsuccessful fix
Exit 1"""Failure Map reference implementation. Python standard library only."""
import json
N = 1
observations = []
def solve(a, b, max_d):
n, m = len(a), len(b)
off = n + m + 1
v = [0] * (2 * off + 2)
for d in range(0, min(max_d, n + m) + 1):
for k in range(-d, d + 1, 2):
if k == -d:
x = v[off + k + 1]
else:
x = v[off + k - 1] + 1
y = x - k
while x < n and y < m and a[x] == b[y]:
x += 1
y += 1
v[off + k] = x
if x >= n and y >= m:
return d
return None
def check(label, actual, expected):
observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
cases = {
1: [('classic example', [['a', 'b', 'c', 'a', 'b', 'b', 'a'], ['c', 'b', 'a', 'b', 'a', 'c'], 20], 5), ('identical', [['x'], ['x'], 5], 0), ('all different', [['a', 'b'], ['c', 'd'], 10], 4), ('cap equal to distance', [['a', 'b', 'c'], ['a', 'b', 'd'], 2], 2), ('cap below distance', [['a', 'b', 'c', 'd'], ['w', 'x', 'y', 'z'], 4], None), ('one side empty', [[], ['q'], 2], 1), ('insert in the middle', [['a', 'a', 'a', 'a'], ['a', 'a', 'b', 'a', 'a'], 4], 1), ('long snakes', [['a', 'b', 'c', 'd', 'e', 'f', 'g', 'h'], ['a', 'b', 'c', 'X', 'd', 'e', 'f', 'g'], 9], 2), ('distance exactly the total length', [['a', 'b'], ['c', 'd', 'e'], 5], 5), ('single edits scattered', [['a', 'b', 'c', 'd', 'e', 'f', 'g'], ['b', 'c', 'd', 'x', 'e', 'f', 'g', 'y'], 12], 3)],
2: [('classic example', [['a', 'b', 'c', 'a', 'b', 'b', 'a'], ['c', 'b', 'a', 'b', 'a', 'c'], 20], 5), ('identical', [['x', 'x'], ['x', 'x'], 5], 0), ('all different', [['a', 'b'], ['c', 'd'], 10], 4), ('cap equal to distance', [['a', 'b', 'c'], ['a', 'b', 'd'], 2], 2), ('cap below distance', [['a', 'b', 'c', 'd'], ['w', 'x', 'y', 'z'], 3], None), ('one side empty', [[], ['q', 'q'], 3], 2), ('insert in the middle', [['a', 'a', 'a', 'a'], ['a', 'a', 'b', 'a', 'a'], 4], 1), ('long snakes', [['a', 'b', 'c', 'd', 'e', 'f', 'g', 'h'], ['a', 'b', 'c', 'X', 'd', 'e', 'f', 'g', 'h'], 9], 1), ('distance exactly the total length', [['a', 'b'], ['c', 'd', 'e'], 5], 5), ('single edits scattered', [['a', 'b', 'c', 'd', 'e', 'f', 'g'], ['b', 'c', 'd', 'x', 'e', 'f', 'g', 'y'], 12], 3)],
3: [('classic example', [['a', 'b', 'c', 'a', 'b', 'b', 'a'], ['c', 'b', 'a', 'b', 'a', 'c'], 20], 5), ('identical', [['x', 'x', 'x'], ['x', 'x', 'x'], 5], 0), ('all different', [['a', 'b'], ['c', 'd'], 10], 4), ('cap equal to distance', [['a', 'b', 'c'], ['a', 'b', 'd'], 2], 2), ('cap below distance', [['a', 'b', 'c', 'd'], ['w', 'x', 'y', 'z'], 4], None), ('one side empty', [[], ['q', 'q', 'q'], 4], 3), ('insert in the middle', [['a', 'a', 'a', 'a'], ['a', 'a', 'b', 'a', 'a'], 4], 1), ('long snakes', [['a', 'b', 'c', 'd', 'e', 'f', 'g', 'h'], ['a', 'b', 'c', 'X', 'd', 'e', 'f', 'g'], 9], 2), ('distance exactly the total length', [['a', 'b'], ['c', 'd', 'e'], 5], 5), ('single edits scattered', [['a', 'b', 'c', 'd', 'e', 'f', 'g'], ['b', 'c', 'd', 'x', 'e', 'f', 'g', 'y'], 12], 3)],
4: [('classic example', [['a', 'b', 'c', 'a', 'b', 'b', 'a'], ['c', 'b', 'a', 'b', 'a', 'c'], 20], 5), ('identical', [['x', 'x', 'x', 'x'], ['x', 'x', 'x', 'x'], 5], 0), ('all different', [['a', 'b'], ['c', 'd'], 10], 4), ('cap equal to distance', [['a', 'b', 'c'], ['a', 'b', 'd'], 2], 2), ('cap below distance', [['a', 'b', 'c', 'd'], ['w', 'x', 'y', 'z'], 3], None), ('one side empty', [[], ['q', 'q', 'q', 'q'], 5], 4), ('insert in the middle', [['a', 'a', 'a', 'a'], ['a', 'a', 'b', 'a', 'a'], 4], 1), ('long snakes', [['a', 'b', 'c', 'd', 'e', 'f', 'g', 'h'], ['a', 'b', 'c', 'X', 'd', 'e', 'f', 'g', 'h'], 9], 1), ('distance exactly the total length', [['a', 'b'], ['c', 'd', 'e'], 5], 5), ('single edits scattered', [['a', 'b', 'c', 'd', 'e', 'f', 'g'], ['b', 'c', 'd', 'x', 'e', 'f', 'g', 'y'], 12], 3)],
5: [('classic example', [['a', 'b', 'c', 'a', 'b', 'b', 'a'], ['c', 'b', 'a', 'b', 'a', 'c'], 20], 5), ('identical', [['x', 'x', 'x', 'x', 'x'], ['x', 'x', 'x', 'x', 'x'], 5], 0), ('all different', [['a', 'b'], ['c', 'd'], 10], 4), ('cap equal to distance', [['a', 'b', 'c'], ['a', 'b', 'd'], 2], 2), ('cap below distance', [['a', 'b', 'c', 'd'], ['w', 'x', 'y', 'z'], 4], None), ('one side empty', [[], ['q', 'q', 'q', 'q', 'q'], 6], 5), ('insert in the middle', [['a', 'a', 'a', 'a'], ['a', 'a', 'b', 'a', 'a'], 4], 1), ('long snakes', [['a', 'b', 'c', 'd', 'e', 'f', 'g', 'h'], ['a', 'b', 'c', 'X', 'd', 'e', 'f', 'g'], 9], 2), ('distance exactly the total length', [['a', 'b'], ['c', 'd', 'e'], 5], 5), ('single edits scattered', [['a', 'b', 'c', 'd', 'e', 'f', 'g'], ['b', 'c', 'd', 'x', 'e', 'f', 'g', 'y'], 12], 3)],
}[N]
for label, args, expected in cases:
check(label, solve(*args), expected)
print(json.dumps({"observations": observations, "passed": all(x["passed"] for x in observations)}, ensure_ascii=False))
raise SystemExit(0 if all(x["passed"] for x in observations) else 1)
| Boundary fixture | Actual | Expected | Outcome |
|---|---|---|---|
| classic example | 7 | 5 | Failed |
| identical | 0 | 0 | Passed |
| all different | 4 | 4 | Passed |
| cap equal to distance | 2 | 2 | Passed |
| cap below distance | None | None | Passed |
| one side empty | 1 | 1 | Passed |
| insert in the middle | 1 | 1 | Passed |
| long snakes | 2 | 2 | Passed |
| distance exactly the total length | 5 | 5 | Passed |
| single edits scattered | None | 3 | Failed |
SHA-256 / 68312ed46e74f2a91d333f1e428f7af41a915e4a6e234a5adf6cc8fcfc122de1
3 / The verified repair
Exit 0"""Failure Map reference implementation. Python standard library only."""
import json
N = 1
observations = []
def solve(a, b, max_d):
n, m = len(a), len(b)
off = n + m + 1
v = [0] * (2 * off + 2)
for d in range(0, min(max_d, n + m) + 1):
for k in range(-d, d + 1, 2):
if k == -d or (k != d and v[off + k - 1] < v[off + k + 1]):
x = v[off + k + 1]
else:
x = v[off + k - 1] + 1
y = x - k
while x < n and y < m and a[x] == b[y]:
x += 1
y += 1
v[off + k] = x
if x >= n and y >= m:
return d
return None
def check(label, actual, expected):
observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
cases = {
1: [('classic example', [['a', 'b', 'c', 'a', 'b', 'b', 'a'], ['c', 'b', 'a', 'b', 'a', 'c'], 20], 5), ('identical', [['x'], ['x'], 5], 0), ('all different', [['a', 'b'], ['c', 'd'], 10], 4), ('cap equal to distance', [['a', 'b', 'c'], ['a', 'b', 'd'], 2], 2), ('cap below distance', [['a', 'b', 'c', 'd'], ['w', 'x', 'y', 'z'], 4], None), ('one side empty', [[], ['q'], 2], 1), ('insert in the middle', [['a', 'a', 'a', 'a'], ['a', 'a', 'b', 'a', 'a'], 4], 1), ('long snakes', [['a', 'b', 'c', 'd', 'e', 'f', 'g', 'h'], ['a', 'b', 'c', 'X', 'd', 'e', 'f', 'g'], 9], 2), ('distance exactly the total length', [['a', 'b'], ['c', 'd', 'e'], 5], 5), ('single edits scattered', [['a', 'b', 'c', 'd', 'e', 'f', 'g'], ['b', 'c', 'd', 'x', 'e', 'f', 'g', 'y'], 12], 3)],
2: [('classic example', [['a', 'b', 'c', 'a', 'b', 'b', 'a'], ['c', 'b', 'a', 'b', 'a', 'c'], 20], 5), ('identical', [['x', 'x'], ['x', 'x'], 5], 0), ('all different', [['a', 'b'], ['c', 'd'], 10], 4), ('cap equal to distance', [['a', 'b', 'c'], ['a', 'b', 'd'], 2], 2), ('cap below distance', [['a', 'b', 'c', 'd'], ['w', 'x', 'y', 'z'], 3], None), ('one side empty', [[], ['q', 'q'], 3], 2), ('insert in the middle', [['a', 'a', 'a', 'a'], ['a', 'a', 'b', 'a', 'a'], 4], 1), ('long snakes', [['a', 'b', 'c', 'd', 'e', 'f', 'g', 'h'], ['a', 'b', 'c', 'X', 'd', 'e', 'f', 'g', 'h'], 9], 1), ('distance exactly the total length', [['a', 'b'], ['c', 'd', 'e'], 5], 5), ('single edits scattered', [['a', 'b', 'c', 'd', 'e', 'f', 'g'], ['b', 'c', 'd', 'x', 'e', 'f', 'g', 'y'], 12], 3)],
3: [('classic example', [['a', 'b', 'c', 'a', 'b', 'b', 'a'], ['c', 'b', 'a', 'b', 'a', 'c'], 20], 5), ('identical', [['x', 'x', 'x'], ['x', 'x', 'x'], 5], 0), ('all different', [['a', 'b'], ['c', 'd'], 10], 4), ('cap equal to distance', [['a', 'b', 'c'], ['a', 'b', 'd'], 2], 2), ('cap below distance', [['a', 'b', 'c', 'd'], ['w', 'x', 'y', 'z'], 4], None), ('one side empty', [[], ['q', 'q', 'q'], 4], 3), ('insert in the middle', [['a', 'a', 'a', 'a'], ['a', 'a', 'b', 'a', 'a'], 4], 1), ('long snakes', [['a', 'b', 'c', 'd', 'e', 'f', 'g', 'h'], ['a', 'b', 'c', 'X', 'd', 'e', 'f', 'g'], 9], 2), ('distance exactly the total length', [['a', 'b'], ['c', 'd', 'e'], 5], 5), ('single edits scattered', [['a', 'b', 'c', 'd', 'e', 'f', 'g'], ['b', 'c', 'd', 'x', 'e', 'f', 'g', 'y'], 12], 3)],
4: [('classic example', [['a', 'b', 'c', 'a', 'b', 'b', 'a'], ['c', 'b', 'a', 'b', 'a', 'c'], 20], 5), ('identical', [['x', 'x', 'x', 'x'], ['x', 'x', 'x', 'x'], 5], 0), ('all different', [['a', 'b'], ['c', 'd'], 10], 4), ('cap equal to distance', [['a', 'b', 'c'], ['a', 'b', 'd'], 2], 2), ('cap below distance', [['a', 'b', 'c', 'd'], ['w', 'x', 'y', 'z'], 3], None), ('one side empty', [[], ['q', 'q', 'q', 'q'], 5], 4), ('insert in the middle', [['a', 'a', 'a', 'a'], ['a', 'a', 'b', 'a', 'a'], 4], 1), ('long snakes', [['a', 'b', 'c', 'd', 'e', 'f', 'g', 'h'], ['a', 'b', 'c', 'X', 'd', 'e', 'f', 'g', 'h'], 9], 1), ('distance exactly the total length', [['a', 'b'], ['c', 'd', 'e'], 5], 5), ('single edits scattered', [['a', 'b', 'c', 'd', 'e', 'f', 'g'], ['b', 'c', 'd', 'x', 'e', 'f', 'g', 'y'], 12], 3)],
5: [('classic example', [['a', 'b', 'c', 'a', 'b', 'b', 'a'], ['c', 'b', 'a', 'b', 'a', 'c'], 20], 5), ('identical', [['x', 'x', 'x', 'x', 'x'], ['x', 'x', 'x', 'x', 'x'], 5], 0), ('all different', [['a', 'b'], ['c', 'd'], 10], 4), ('cap equal to distance', [['a', 'b', 'c'], ['a', 'b', 'd'], 2], 2), ('cap below distance', [['a', 'b', 'c', 'd'], ['w', 'x', 'y', 'z'], 4], None), ('one side empty', [[], ['q', 'q', 'q', 'q', 'q'], 6], 5), ('insert in the middle', [['a', 'a', 'a', 'a'], ['a', 'a', 'b', 'a', 'a'], 4], 1), ('long snakes', [['a', 'b', 'c', 'd', 'e', 'f', 'g', 'h'], ['a', 'b', 'c', 'X', 'd', 'e', 'f', 'g'], 9], 2), ('distance exactly the total length', [['a', 'b'], ['c', 'd', 'e'], 5], 5), ('single edits scattered', [['a', 'b', 'c', 'd', 'e', 'f', 'g'], ['b', 'c', 'd', 'x', 'e', 'f', 'g', 'y'], 12], 3)],
}[N]
for label, args, expected in cases:
check(label, solve(*args), expected)
print(json.dumps({"observations": observations, "passed": all(x["passed"] for x in observations)}, ensure_ascii=False))
raise SystemExit(0 if all(x["passed"] for x in observations) else 1)
| Boundary fixture | Actual | Expected | Outcome |
|---|---|---|---|
| classic example | 5 | 5 | Passed |
| identical | 0 | 0 | Passed |
| all different | 4 | 4 | Passed |
| cap equal to distance | 2 | 2 | Passed |
| cap below distance | None | None | Passed |
| one side empty | 1 | 1 | Passed |
| insert in the middle | 1 | 1 | Passed |
| long snakes | 2 | 2 | Passed |
| distance exactly the total length | 5 | 5 | Passed |
| single edits scattered | 3 | 3 | Passed |
SHA-256 / 8bad4b44c7b60425a70c4a5ba911234e10e344687ab380b3a903f77cb79e203a
Verification & scope
A deterministic, bounded teaching model of one diff, patch or merge rule with stipulated conventions; it is not a production diff or version-control implementation and makes no claim of conformance to any specific tool. This reproducer isolates one failure mechanism. Results cover the supplied fixtures. Variants within a family share a test contract and should remain grouped when constructing evaluation splits. Related mechanisms with a shared evaluation_group must also remain together; these controlled models are not independent production incidents.
Observations recorded using Python 3.12.14 at 2026-09-29T14:49:05.866445+00:00.
Case digest / fb216fed42319c0c48aeaa188639907d021d0842e67ab742389c17221f84145e