#include <bits/stdc++.h>
using namespace std;
int main() {
  int n = 0, i = 0, j = 0, count1 = 0, count2 = 0, s = 0;
  char a[100100] = {};
  char maru = 'o', batu = 'x';
  cin >> n;
  scanf("%s", a);
  for (i = 0; i < n; i++) {
    if (a[i] == maru) {
      count1++;
      count2 = 0;
      if (count1 == 2) break;
      s++;
    }
    if (a[i] == batu) {
      count2++;
      count1 = 0;
      if (count2 == 2) break;
      s++;
    }
  }
  cout << s << endl;
  return 0;
}
