#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using pii = pair<int, int>;
using piii = pair<pii, pii>;
const int dx[4] = {0, -1, 1, 0};
const int dy[4] = {-1, 0, 0, 1};
const int INF = 1e9 + 7;
int gcd(int x, int y) {
  if (x < y) swap(x, y);
  if (y == 0) return x;
  return gcd(y, x % y);
}
template <class T1, class T2>
void chmin(T1 &a, T2 b) {
  if (a > b) a = b;
}
template <class T1, class T2>
void chmax(T1 &a, T2 b) {
  if (a < b) a = b;
}
template <class T>
void Add(T &a, const T &b, const T &mod = 1000000007) {
  int val = ((a % mod) + (b % mod)) % mod;
  if (val < 0) {
    val += mod;
  }
  a = val;
}
int main() {
  int N;
  string S;
  cin >> N >> S;
  int ans = INF;
  int key1[200100] = {};
  for (int i = 0; i < N; ++i) {
    key1[i + 1] += key1[i];
    if (S[i] == '.') {
      key1[i + 1]++;
    }
  }
  for (int i = 1; i <= N; ++i) {
    int key = 0;
    key += (i - key1[i]);
    key += (key1[N] - key1[i]);
    ans = min(ans, key);
  }
  cout << ans << endl;
  return 0;
}
