#include <bits/stdc++.h>
#define rep(i,n) for(int i = 0; i < (n); ++i)
#define srep(i,s,t) for (int i = s; i < t; ++i)
#define drep(i,n) for(int i = (n)-1; i >= 0; --i)
using namespace std;
typedef long long int ll;
typedef pair<int,int> P;
#define yn {puts("Yes");}else{puts("No");}
#define MAX_N 200005

int is_kaibun(string str){
    int m = str.size();
    int res = 1;
    for(int i = 0; i < m / 2; i++){
        if(str[i] != str[m-1-i]){
            res = 0;
            break;
        }
    }
    return res;
}

int main() {
    string s;
    cin >> s;
    int ans = 0;
    int n = s.size();
    rep(i,n){
        srep(j,i,n){
            if(i == 0 && j == n - 1)continue;
            string t;
            srep(k,i,j+1){
                t += s[k];
            }
            if(is_kaibun(t))ans = max(ans, (int)t.size());
        }
    }
    cout << ans << endl;
    return 0;
}