#include <bits/stdc++.h>
#define rep(i, a) rep2 (i, 0, a)
#define rep2(i, a, b) for (int i = (a); i < (b); i++)
#define repr(i, a) repr2 (i, 0, a)
#define repr2(i, a, b) for (int i = (b) - 1; i >= (a); i--)
using namespace std;
typedef long long ll;

bool ispal(string s) {
	rep (i, s.length()) {
		if (s[i] != s[s.length() - 1 - i]) return false;
	}
	return true;
}

int main() {
	string s;
	cin >> s;
	int ans = 1;
	rep (i, s.length()) {
		rep2 (j, i, s.length()) {
			if (i == 0 && j == s.length() - 1) continue;
			if (ispal(s.substr(i, j - i + 1))) {
				ans = max(ans, j - i + 1);
			}
		}
	}
	cout << ans << endl;

    return 0;
}