# coding: utf-8
import array, bisect, collections, copy, heapq, itertools, math, random, re, string, sys, time
sys.setrecursionlimit(10 ** 7)
INF = 10 ** 20
MOD = 10 ** 9 + 7


def II(): return int(input())
def ILI(): return list(map(int, input().split()))
def IAI(LINE): return [ILI() for __ in range(LINE)]
def IDI(): return {key: value for key, value in ILI()}


def read():
    S = str(input())
    return (S,)


def is_kaibun(l_char):
    for i in range(len(l_char) // 2):
        if not l_char[i] == l_char[len(l_char) - i - 1]:
            return False

    return True


def solve(S):
    ans = 1
    bool_outer = False
    for i in range(len(S) - 1, 1, -1):
        for j in range(len(S) - i + 1):
            l_char = S[j:i + j]
            if is_kaibun(l_char):
                ans = i
                bool_outer = True
                break

        if bool_outer:
            break

    return ans


def main():
    params = read()
    print(solve(*params))


if __name__ == "__main__":
    main()