#include <bits/stdc++.h>
template <typename T>
T gcd(T a, T b) {
  return b == 0 ? a : gcd(b, a % b);
}
template <typename T>
T lcm(T a, T b) {
  return a * b / gcd(a, b);
}
template <typename T>
T clamp(T val, T min, T max) {
  return val < min ? min : (max < val ? max : val);
}
template <typename T>
size_t max_index(T begin, T end) {
  return distance(begin, max_element(begin, end));
}
template <typename T>
size_t min_index(T begin, T end) {
  return distance(begin, min_element(begin, end));
}
using namespace std;
signed main(void) {
  cin.tie(0);
  ios::sync_with_stdio(false);
  long long num;
  long long tmp;
  long long n;
  cin >> n;
  string s;
  cin >> s;
  num = n;
  tmp = 0;
  for (long long i = 0; i < n; ++i) {
    if (s[i] != '.') tmp++;
  }
  num = min(tmp, num);
  tmp = 0;
  for (long long i = 0; i < n; ++i) {
    if (i != n - 1) {
      if (s[i] != '.') tmp++;
    } else {
      if (s[i] != '#') tmp++;
    }
  }
  num = min(tmp, num);
  tmp = 0;
  for (long long i = 0; i < n; ++i) {
    if (s[i] != '#') tmp++;
  }
  num = min(tmp, num);
  tmp = 0;
  for (long long i = 0; i < n; ++i) {
    if (i == 0) {
      if (s[0] != '.') tmp++;
    } else {
      if (s[i] != '#') tmp++;
    }
  }
  num = min(tmp, num);
  cout << num << endl;
  return 0;
}
