while True:
try:
str_1 = list(input())
str_2 = list(input())
len_1 = len(str_1)
len_2 = len(str_2)
a = []
for i in range(len_1 + 1):
b = []
for j in range(len_2 + 1):
b.append(i + j)
a.append(b)
for i in range(1,len_1 + 1):
for j in range(1,len_2 + 1):
if(str_1[i - 1] == str_2[j - 1]):
d = 0
else:
d = 1
a[i][j] = min(a[i - 1][j] + 1,a[i][j - 1] + 1,a[i-1][j-1] + d)
print(a[len_1][len_2])
except:
break