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