#include <bits/stdc++.h>

using namespace std;

int main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  int N;
  string S;

  cin >> N >> S;
  int cnt = 0;
  for ( int i = 0; i < N; i++ ) {
    if ( S[i] == 'x' ) cnt++;
    else cnt = 0;
    if ( cnt == 2 ) {
      cout << i << endl;
      return 0;
    }
  }

  cout << N << endl;
  
  return 0;
}