s1 = input()
s2 = input()
global l
l = list()
for i in range(1001):
l.append([])
for j in range(1001):
l[i].append(0)
def f(s1: str, s2: str, i: int, j: int):
if i == 0 or j == 0:
a = i + j
return a
if l[i][j] != 0:
return l[i][j]
elif s1[i-1] == s2[j-1]:
a = f(s1, s2, i - 1, j - 1)
else:
a = min(
1 + f(s1, s2, i - 1, j),
min(1 + f(s1, s2, i, j - 1), 1 + f(s1, s2, i - 1, j - 1)),
)
l[i][j] = a
return a
a = f(s1, s2, len(s1) , len(s2) )
print(a)

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