import java.util.Scanner;

public class Main {
	public static void main(String[] args) {

		Scanner scanner = new Scanner(System.in);
		int N = scanner.nextInt();
		String str = scanner.next();
		String[] S1 = new String[N];
		int[] S2 = new int[N];
		int count = 0;

		for (int i = 0; i < N; i++) {
			String str2 = String.valueOf(str.charAt(i));
			S1[i] = str2;
		}

		for (int i = 0; i < N; i++) {
			if (S1[i].equals(".")) {
				S2[i] = 1;
			} else {
				S2[i] = 0;
			}
		}

		for (int i = 0; i < N; i++) {
			if (S2[i] == 0) {
				for (int j = i; j < N; j++) {
					if (S2[j] == 1) {
						count += 1;
					}
				}
				break;
			}
		}

		System.out.println(count);

		//	for (int i = 0; i < N; i++) {
		//		System.out.println(S2[i]);
		//	}
	}
}