#include <bits/stdc++.h>
using namespace std;
int main() {
  int n;
  cin >> n;
  string s;
  cin >> s;
  int cnt = 0;
  for (int i = 1; i < n; i++) {
    if (s[i - 1] == 'x' && s[i] == 'x') break;
    cnt++;
  }
  cout << cnt << endl;
}
