#include <bits/stdc++.h>
using namespace std;
inline int toInt(string s) {
  int v;
  istringstream sin(s);
  sin >> v;
  return v;
}
template <class T>
inline string toString(T x) {
  ostringstream sout;
  sout << x;
  return sout.str();
}
template <typename T>
T gcd(T x, T y) {
  if (y == 0)
    return x;
  else
    return gcd(y, x % y);
}
template <typename T>
T lcm(T a, T b) {
  return a / gcd(a, b) * b;
}
template <typename T>
bool is_prime(T n) {
  for (int i = 2; i * i <= n; i++) {
    if (n % i == 0) return false;
  }
  return n != 1;
}
map<long long, long long> prime_factor(long long n) {
  map<long long, long long> res;
  for (int i = 2; i * i <= n; i++) {
    while (n % i == 0) {
      ++res[i];
      n /= i;
    }
  }
  if (n != 1) res[n] = 1;
  return res;
}
int extgcd(int a, int b, int &x, int &y) {
  int d = a;
  if (b != 0) {
    d = extgcd(b, a % b, y, x);
    y -= (a / b) * x;
  } else {
    x = 1;
    y = 0;
  }
  return d;
}
long long mod_pow(long long x, long long n, long long mod) {
  if (n == 0) return 1;
  long long res = mod_pow(x * x % mod, n / 2, mod);
  if (n & 1) res = res * x % mod;
  return res;
}
long long comb(long long a, long long b, long long mod) {
  long long mul = 1;
  long long div = 1;
  for (int i = (0); i < (b); ++i) {
    mul *= (a - (long long)i);
    mul %= mod;
    div *= ((long long)i + 1);
    div %= mod;
  }
  mul *= mod_pow(div, mod - 2, mod);
  return mul % mod;
}
vector<string> split(const string &str, char delim) {
  vector<string> res;
  size_t current = 0, found;
  while ((found = str.find_first_of(delim, current)) != string::npos) {
    res.push_back(string(str, current, found - current));
    current = found + 1;
  }
  res.push_back(string(str, current, str.size() - current));
  return res;
}
bool is_kadomatsu(int a, int b, int c) {
  if (a == b || a == c || b == c) return false;
  if (a > b && c > b) return true;
  if (a < b && c < b) return true;
  return false;
}
struct UF {
  int n;
  vector<int> d;
  UF() {}
  UF(int n) : n(n), d(n, -1) {}
  int root(int v) {
    if (d[v] < 0) return v;
    return d[v] = root(d[v]);
  }
  bool same(int a, int b) { return root(a) == root(b); }
  bool unite(int x, int y) {
    x = root(x);
    y = root(y);
    if (x == y) return false;
    if (size(x) < size(y)) swap(x, y);
    d[x] += d[y];
    d[y] = x;
    return true;
  }
  int size(int v) { return -d[root(v)]; }
};
struct Fibonacci {
  vector<vector<long long int>> fib;
  Fibonacci() {
    fib.resize(2, vector<long long int>(2));
    fib[0][0] = 1;
    fib[0][1] = 1;
    fib[1][0] = 1;
    fib[1][1] = 0;
  }
  vector<vector<long long int>> mul(vector<vector<long long int>> &A,
                                    vector<vector<long long int>> &B) {
    vector<vector<long long int>> C(2, vector<long long int>(2));
    for (int i = (0); i < (2); ++i) {
      for (int k = (0); k < (2); ++k) {
        for (int j = (0); j < (2); ++j) {
          C[i][j] = (C[i][j] + A[i][k] * B[k][j]) % 1000000007LL;
        }
      }
    }
    return C;
  }
  long long pow(long long n) {
    vector<vector<long long int>> A = fib;
    vector<vector<long long int>> B(2, vector<long long int>(2));
    for (int i = (0); i < (2); ++i) {
      B[i][i] = 1;
    }
    while (n > 0) {
      if (n & 1) B = mul(B, A);
      A = mul(A, A);
      n >>= 1;
    }
    return B[1][0];
  }
};
vector<int> divisor(int n) {
  if (n == 1) return {};
  vector<int> res;
  for (int i = 1; i * i <= n; i++) {
    if (n % i == 0) {
      res.emplace_back(i);
      if (i != 1 && i != n / i) res.emplace_back(n / i);
    }
  }
  return res;
}
struct Bellmanford {
  int n;
  struct edge {
    int from, to, cost;
  };
  vector<edge> E;
  vector<int> d;
  Bellmanford(int n) : n(n), d(n) { E.resize(n); }
  void add_edge(int x, int y, int cost) {
    edge e;
    e.from = x;
    e.to = y;
    e.cost = cost;
    E.push_back(e);
  }
  void shortest_path(int s) {
    for (int i = (0); i < (n); ++i) d[i] = (1001000000);
    d[s] = 0;
    while (true) {
      bool update = false;
      for (auto e : E) {
        if (d[e.from] != (1001000000) && d[e.to] > d[e.from] + e.cost) {
          d[e.to] = d[e.from] + e.cost;
          update = true;
        }
      }
      if (!update) break;
    }
  }
};
struct Dijkstra {
  int n;
  struct edge {
    int to;
    long long cost;
  };
  vector<vector<edge>> G;
  vector<long long int> d;
  Dijkstra(int n) : n(n), d(n) { G.resize(n); }
  void add_edge(int x, int y, long long cost) {
    edge e;
    e.to = y;
    e.cost = cost;
    G[x].push_back(e);
  }
  void shortest_path(int s) {
    for (int i = (0); i < (n); ++i) d[i] = 100000000000000000;
    d[s] = 0;
    priority_queue<pair<long long, int>, vector<pair<long long, int>>,
                   greater<pair<long long, int>>>
        que;
    que.push(make_pair(0, s));
    while (!que.empty()) {
      pair<int, int> p = que.top();
      que.pop();
      int v = p.second;
      if (d[v] < p.first) continue;
      for (auto e : G[v]) {
        if (d[e.to] > d[v] + e.cost) {
          d[e.to] = d[v] + e.cost;
          que.push(make_pair(d[e.to], e.to));
        }
      }
    }
  }
};
struct Segmenttree {
  int n;
  vector<int> dat;
  Segmenttree(int n_) {
    n = 1;
    while (n < n_) n *= 2;
    dat = vector<int>(2 * n - 1, 0);
  }
  void add(int idx, long long val) {
    idx += n - 1;
    dat[idx] += val;
    while (idx > 0) {
      idx = (idx - 1) / 2;
      dat[idx] += val;
    }
  }
  int query(int a, int b) { return query_seg(a, b, 0, 0, n); }
  int query_seg(int a, int b, int k, int l, int r) {
    if (r <= a || b <= l) return 0;
    if (a <= l && r <= b)
      return dat[k];
    else {
      return query_seg(a, b, k * 2 + 1, l, (l + r) / 2) +
             query_seg(a, b, k * 2 + 2, (l + r) / 2, r);
    }
  }
};
struct Trie {
  Trie *next[26];
  Trie() { fill(next, next + 26, (Trie *)0); }
  void insert(char *s) {
    if (*s == '\0') return;
    if (this->next[*s - 'a'] == NULL) {
      this->next[*s - 'a'] = new Trie();
    }
    this->next[*s - 'a']->insert(s + 1);
  }
  bool find(char *s) {
    if (*s == '\0') return true;
    if (this->next[*s - 'a'] == NULL) {
      return false;
    }
    return this->next[*s - 'a']->find(s + 1);
  }
};
struct BIT {
  int n;
  vector<int> bit;
  BIT() {}
  BIT(int n) : n(n) { bit.resize(n + 1); }
  int sum(int i) {
    int s = 0;
    while (i > 0) {
      s += bit[i];
      i -= i & -i;
    }
    return s;
  }
  void add(int i, int x) {
    while (i <= n) {
      bit[i] += x;
      i += i & -i;
    }
  }
};
int main() {
  cin.tie(0);
  ios::sync_with_stdio(false);
  int N;
  string S;
  cin >> N >> S;
  int all_w = 0;
  for (int i = (0); i < (N); ++i) {
    if (S[i] == '.') all_w++;
  }
  int tmp_w = 0;
  int ans = 11111111;
  for (int i = (0); i < (N); ++i) {
    int tmp = (i - tmp_w) + (N - i - (N - all_w - tmp_w));
    ans = min(tmp, ans);
    if (S[i] == '.') tmp_w++;
  }
  ans = min(ans, N - all_w);
  cout << (ans) << endl;
  ;
  return 0;
}
