def check(s):
    l = len(s)

    ma = 0
    for i in range(l):
        for j in range(i, l):
            for k in range((j - i) // 2 + 1):
                if s[i + k] != s[j - k]:
                    break
            else:
                ma = max(ma, j - i + 1)
    return ma


def solve():
    S = input()

    print(max(check(S[1:]), check(S[:-1])))


if __name__ == '__main__':
    solve()