# import sys; input = sys.stdin.buffer.readline
# sys.setrecursionlimit(10**7)
from collections import defaultdict
con = 10 ** 9 + 7; INF = float("inf")
from math import gcd

def getlist():
	return list(map(int, input().split()))

def judge(n, s):
	jud = "Yes"
	for i in range(n):
		if s[i] != s[-1 - i]:
			jud = "No"

	return jud

#処理内容
def main():
	S = input()
	N = len(S)
	ans = 0
	for i in range(N + 1):
		for j in range(i + 1, N + 1):
			s = S[i:j]
			n = len(s)
			if N != n:
				val = judge(n, s)
				if val == "Yes":
					ans = max(ans, n)

	print(ans)

if __name__ == '__main__':
	main()