#include <iostream>
#include <iomanip>
#include <vector>
#include <algorithm>
#include <numeric>
#include <functional>
#include <cmath>
#include <queue>
#include <stack>
#include <string>

#define repd(i,a,b) for (int i=(a);i<(b);i++)
#define rep(i,n) repd(i,0,n)
typedef long long ll;

using namespace std;


int inputValue(){
    int a;
    cin >> a;
    return a;
};

void inputArray(int * p, int a){
    rep(i, a){
        cin >> p[i];
    }
};

void inputVector(vector<int> * p, int a){
    rep(i, a){
        int input;
        cin >> input;
        p -> push_back(input);
    }
}

template <typename T>
void output(T a, int precision) {
    if(precision > 0){
        cout << setprecision(precision)  << a << "\n";
    }
    else{
        cout << a << "\n";
    }
}

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


int main(int argc, const char * argv[]) {
    
    // source code
    string str;
    cin >> str;
    int ret = 1;
    rep(i, (int)str.length()){
        repd(j, i, (int)str.length()){
            if (isReverse(str.substr(i, j - i + 1)) && j - i + 1 != str.length()) {
                ret = max(ret, j - i + 1);
            }
        }
    }
    output(ret, 0);
    return 0;
}