#include <bits/stdc++.h>

const static double	de_PI	= 3.14159265358979323846;
const static int	de_MOD	= 1000000007;
const static int	de_MAX	= 999999999;
const static int	de_MIN = -999999999;

int main(void) {

	//std::ifstream in("123.txt");	std::cin.rdbuf(in.rdbuf());

	std::string S;
	std::cin >> S;
	
	unsigned int max = 1;
	for (unsigned int i = 0; i < S.length() - 1; i++) {
		unsigned int temp = 0;
		for (unsigned int j = S.length() - 1; j > i; j--) {
			if (j == S.length() - 1 && i == 0) {
				continue;
			}
			if (S[i] == S[j]) {
				bool flg = true;
				temp = j - i + 1;
				unsigned int k = 1;
				while (k <= temp / 2 - 1) {
					if (S[i + k] != S[j - k]) {
						flg = false;
						break;
					}
					k++;
				}
				if (flg) {
					if (temp > max) {
						max = temp;
						break;
					}
				}
			}
		}
	}

	std::cout << max << std::endl;

}