def is_palindrome(s):
    return s == s[::-1]


def f(s):
    if len(s) == 1:
        return 1

    result = 0
    for i in range(1, len(s)):
        a, b = s[:i], s[i:]
        if not is_palindrome(a):
            continue
        result = max(result, len(a))
        if is_palindrome(b):
            result = max(result, len(b))
        else:
            result = max(result, f(b))
    return result


S = input()

print(f(S))