#include <bits/stdc++.h>

using namespace std;

typedef long double ld;
typedef long long ll;
typedef pair<int,int> ii;
typedef pair<double,double> dd;
typedef vector<int> vi;
typedef vector<ll> vll;
typedef vector<vector<int>> vvi;
typedef vector<ii> vii;

int main(){
    ios::sync_with_stdio(false);
    int N; cin >> N;
    string I; cin >> I;
    string s(I);
    for(int i = 0; i < N; ++i) s[i] = I[N-1-i];
    // cout << s << endl;
    for(int i=N-1; i>=0; --i) {
        bool valid = true;
        for(int j = 0; j <= i/2; ++j) {
            if (s[j] != s[i-j]) {
                valid = false;
                break;
            }
        }
        if (valid) {
            cout << N-i-1 << endl;
            break;
        }
    }

}