import itertools

S = input()
L = len(S)
is_palindrome = lambda s: s[:len(s) // 2] == s[-1:(-len(s) - 1) // 2:-1]

ans = 1
for i, j in itertools.combinations(range(L + 1), 2):
    if is_palindrome(S[i:j]) and j - i != L:
        ans = max(ans, j - i)
print(ans)