#include <bits/stdc++.h>
int n;
char c;
int main() {
  int i, err, ans;
  scanf("%d", &n);
  for (i = err = 0; i < n; i++) {
    scanf("%c", &c);
    if (c == 'x')
      if (err == 1) {
        ans = i - 1;
        goto END;
      } else
        err = 1;
    else
      err = 0;
  }
  ans = n;
END:
  printf("%d\n", ans);
  return (0);
}
