#include <bits/stdc++.h>

using namespace std;

int main() {
    int n;
    cin >> n;
    string s;
    cin >> s;
    bool reach = false;
    int cnt = 0;
    for (int i = 0; i < n; i++) {
        if (s[i] == 'o') {
            reach = false;
        } else if (reach) {
            cout << cnt << endl;
            return 0;
        } else {
            reach = true;
        }
        cnt++;
    }
    cout << cnt << endl;
    return 0;
}