题解 | #查找两个字符串a,b中的最长公共子串#

import sys

a=input()
b=input()
c=len(a)
d=len(b)
max=0
e=''
if c<=d:
    for i in range(c):
        for j in range(i+1,c+1):
            if a[i:j] in b and len(a[i:j])>max:
                e=a[i:j]
                max=len(a[i:j])
else:
    for i in range(d):
        for j in range(i+1,d+1):
            if b[i:j] in a and len(b[i:j])>max:
                e=b[i:j]
                max=len(b[i:j])


print(e)