题解 | #最长回文子串#
import sys
for line in sys.stdin:
s1=line.strip()
len1=len(s1)
result=[]
for i in range(len1):
for j in range(len1, 0, -1):
if s1[i:j]==s1[i:j][::-1]:
result.append(j-i)
print(max(result))