题解 | #最长回文子串#

# 20241014
s = input().lower()
p = 0
for i in range(len(s)):
    for j in range(i+1,len(s)):
        if s[i:j+1] == s[i:j+1][::-1] and j+1-i > p:
            p = j+1-i
print(p)