题解 | #查找两个字符串a,b中的最长公共子串#

from re import I

a = input().strip()
b = input().strip()
len1 = min(len(a), len(b))
just1 = False
list1 = []
for i in range(len1, -1, -1):
    try:
        for k in range(0, len(a) - i):
            if a[k : k + i] in b:
                just1 = True
                len2 = i
                list1.append(a[k : k + i])
        if just1:
            break
    except:
        continue
if len1 == len(a):
    for i in range(0, len(a) - len2):
        if a[i : i + len2] in list1:
            print(a[i : i + len2])
            break
elif len1 == len(b):
    for i in range(0, len(b) - len2):
        if b[i : i + len2] in list1:
            print(b[i : i + len2])
            break