#include "bits/stdc++.h"
#include <boost/range/irange.hpp>
using namespace std;
using boost::irange;

// 定義
typedef long long           ll;
typedef pair<ll, ll>        P;
#define ALL(x)              (x).begin(),(x).end()
#define REP(i, n)           for (ll i = 0 ; i < (ll)n ; ++i)
#define REPN(i, m, n)       for (ll i = m ; i < (ll)n ; ++i)
const ll                    INF = 2e9;
const ll                    INF_LL = 1LL<<60;
const ll                    MOD = 998244353;

ll Ceil(ll val, ll div)   { return (val + div - 1) / div; }
ll CeilN(ll val, ll div)  { return Ceil(val, div) * div; }
ll FloorN(ll x, ll n)     { return (x - x % n); }
bool IsOdd(ll x)          { return ((x & 1) == 1); }
bool IsEven(ll x)         { return ((x & 1) == 0); }
template<class T> bool chmax(T& a, T b) { if (a < b) { a = b; return 1; } return 0; }
template<class T> bool chmin(T& a, T b) { if (a > b) { a = b; return 1; } return 0; }

// 処理
void Solve()
{
	ll N;
	string S;
	cin >> N >> S;

	ll idx = S.find('#');
	ll ans = 0; 
	if (idx != string::npos) {
		bool isKuro = true;
		for (auto i : irange<ll>(idx + 1, S.size(), 1)) {
			if (S[i] == '.') {
				if (isKuro) {
					isKuro = false;
					ans++;
				}
			}  else {
				isKuro = true;
			}
		}
	}

	cout << ans << endl;
}

// メイン
int main()
{
	cin.tie(nullptr);
	ios_base::sync_with_stdio(false);
	cout << fixed << setprecision(15);
	Solve();
	return 0;
}
