#include "bits/stdc++.h"
using namespace std;
#define ll long long int
#define rep(i,n) for( int i = 0; i < n; i++ )
#define rrep(i,n) for( int i = n; i >= 0; i-- )
#define REP(i,s,t) for( int i = s; i <= t; i++ )
#define RREP(i,s,t) for( int i = s; i >= t; i-- )
#define dump(x)  cerr << #x << " = " << (x) << endl;
#define INF 2000000000
#define mod 1000000007
#define INF2 1000000000000000000

int check(string S) {
	int len = S.length();
	rep(i, len / 2) {
		if (S[i] != S[len - i - 1]) return 0;
	}
	return len;
}

int main(void)
{
    cin.tie(0);
    ios::sync_with_stdio(false);
	string S; cin >> S;
	int ans = 0;
	rep(j, S.length() - 1) {
		rep(i, (int)S.length() - 1 - j) {
			string sub1 = S.substr(j, i + 1);
			string sub2 = S.substr(i + 1, S.length() - i - 1);
			ans = max({ ans, check(sub1), check(sub2) });
		}
	}
	cout << ans << endl;



    return 0;
}