#include <bits/stdc++.h>
using namespace std;
int countcolour2(string& s, int n) {
  int count;
  vector<int> v(n + 1);
  for (int i = 0; i < n + 1; i++) {
    count = 0;
    for (int j = 0; j < n; j++) {
      if ((j < i && s.at(j) == '#') || ((j >= i && s.at(j) == '.'))) {
        count++;
      }
    }
    v.at(i) = count;
  }
  int minnum = v.at(0);
  for (int i = 0; i < n + 1; i++) {
    if (v.at(i) < minnum) {
      minnum = v.at(i);
    }
  }
  return minnum;
}
int main() {
  int n;
  string s;
  cin >> n;
  cin >> s;
  cout << ":-)" << countcolour2(s, n) << endl;
}
