#include <bits/stdc++.h>
using namespace std;
const long long MOD = 1000000007;
const long double PI = acos(-1);
const long double EPS = 0.0000000001;
int main() {
  string n, s;
  cin >> n >> s;
  bool flag = false;
  int cnt = 0;
  for (int i = 0; i < s.size(); i++) {
    if (!flag && s[i] == '.') continue;
    flag = true;
    if (s[i] == '.') cnt += 1;
  }
  cout << cnt << endl;
}
