#include <bits/stdc++.h>
using namespace std;
int Gcd(int a, int b) {
  if (b == 0) return a;
  return Gcd(b, a % b);
}
int Lcm(int a, int b) { return a / Gcd(a, b) * b; }
inline int read() {
  int f = 1, x = 0;
  char ch = getchar();
  while (ch > '9' || ch < '0') {
    if (ch == '-') f = -f;
    ch = getchar();
  }
  while (ch >= '0' && ch <= '9') {
    x = x * 10 + ch - '0';
    ch = getchar();
  }
  return x * f;
}
const int maxn = 1e5 + 10;
int main() {
  int n = read();
  string s;
  cin >> s;
  int cnt1 = 0, cnt2 = 0;
  for (int i = 0; i < n; i++) {
    if (s[i] == '#') {
      cnt1++;
    } else {
      cnt2++;
    }
  }
  if (cnt1 > 0) {
    cout << cnt2 << endl;
  } else {
    cout << 0 << endl;
  }
  return 0;
}
