#include <bits/stdc++.h>
using namespace std;
#define REP(i,n) for (int i=0;i<(n);i++)
#define REP2(i,m,n) for (int i=m;i<(n);i++)
typedef long long ll;


int main() {
    int N; cin >> N;
    string S; cin >> S;

    bool prev = false;
    REP(i, N) {
        if (S[i] == 'x') {
            if (prev) {
                cout << i << endl;
                return 0;
            }
            prev = true;
        } else {
            prev = false;
        }
    }

    cout << N << endl;
}