题解 | #公共子串计算#

from re import I
import sys

s1 = input()
s2 = input()

l1 = len(s1)
l2 = len(s2)

dp = [[0] * (l1+1) for _ in range(l2+1)]
max_child_len = 0
# end_index = 0
for column in range(l1):
    dp[0][column] = 0
for row in range(l2):
    dp[row][0] = 0

for row in range(1, l2+1):
    for column in range(1, l1+1):
        if s1[column-1] == s2[row-1]:
            dp[row][column] = dp[row-1][column-1]+1
            if max_child_len < dp[row][column]:
                max_child_len = dp[row][column]
                # end_index = i
        else:
            dp[row][column] = 0

print(max_child_len)