#include <bits/stdc++.h>
using namespace std;
int main() {
  int n, p = 0;
  int a[200000];
  string s;
  cin >> n >> s;
  for (int i = 0; i < n; i++) {
    if (s[i] == '.') p++;
    a[i] = p;
  }
  int m = n;
  for (int i = 0; i < n; i++) m = min(p + i + 1 - a[i] * 2, m);
  cout << m << endl;
  return 0;
}
