#include <bits/stdc++.h>
#include<iostream>
#include<iomanip>
#include<string>
#include<algorithm>
#include<vector>
#include<set>
#include<list>
#include<queue>
#include<math.h>
#include<bitset>
using ll = long long;
using namespace std;

int main()
{
    string s;
    int max1 = 1;
    cin >> s;
    int n = s.size();
    for (int i = 0; i < n-1; i++){
        for (int j = n-1; j > i; j--){
            bool par = true;
            int f = i, b = j;
            if (f == 0 && b == n-1) continue;
            while (f <= b){
                if (s[f++] != s[b--]) {
                    par = false;
                    break;
                }
            }
            if (par) max1 = max(max1, j-i+1);
        }
    }
    cout << max1 << endl;
}