# -*-coding:utf-8-*-
while True:
        try:
            input_s = input()
            n = 0
            for i in range(len(input_s)):
                for j in range(i + 1 , len(input_s) + 1):
                    pe_s = input_s[i:j]
                    l = len(pe_s)
                    if pe_s == pe_s[::-1] and j - i > n:
                        n = j - i
            print(n)
        except:
            break