#include <bits/stdc++.h>
using namespace std;
const int INF = 1e9;
int main() {
  int n;
  string s;
  cin >> n >> s;
  int cnt = 0;
  for (int i = 0; i < n; i++) {
    if (s[i] == '.') cnt++;
  }
  int ans = n;
  for (int i = 0; i < n; i++) {
    if (s[i] == '.')
      cnt--;
    else
      cnt++;
    ans = min(ans, cnt);
  }
  cout << ans << endl;
  return 0;
}
