Problem: There are N stones arranged in a row. Every stone is painted white or black. A string S represents the color of the stones. The i-th stone from the left is white if the i-th character of S is `.`, and the stone is black if the character is `#`.

Takahashi wants to change the colors of some stones to black or white so that there will be no white stone immediately to the right of a black stone. Find the minimum number of stones that needs to be recolored.

Constraints

* 1 \leq N \leq 2\times 10^5
* S is a string of length N consisting of `.` and `#`.

Input

Input is given from Standard Input in the following format:


N
S


Output

Print the minimum number of stones that needs to be recolored.

Examples

Input

3
#.#


Output

1


Input

3
.#


Output

1


Input

5
.##.


Output

2


Input

9
.........


Output

0

Solution (in JAVA):

Solution:
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.ArrayList;
import java.util.List;

/*Atcoder用
 * 		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
		String[] tmp = br.readLine().split(" ");
		int a = Integer.parseInt(tmp[0]);
		int b = Integer.parseInt(tmp[1]);
		int c = Integer.parseInt(tmp[2]);


		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
		String get = br.readLine();
		char[] s = get.toCharArray();
		for(char c:s)System.out.println(c);

		List<Integer> ls = new ArrayList<Integer>();
		String[] tmp = br.readLine().split(" ");
		for (int n = 0; n < N; n++) {
			ls.add(Integer.parseInt(tmp[n]));
		}
 */

public class Main {

	public static void main(String[] args) throws IOException {
 		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
		String num = br.readLine();
		int N = Integer.parseInt(num);
		String get = br.readLine();
		char[] S = get.toCharArray();

		List<Integer> whiteNum = new ArrayList<Integer>();
		List<Integer> blackNum = new ArrayList<Integer>();

		//TODO: testCase 1 # でバグ
		//		おそらくマスの目まで計算している

		int count = 0;
		for(int i = 0;i<S.length;i++){
			if(S[i] == '.')count++;
			whiteNum.add(count);

		}
		count = 0;
		int memory = 0;
		for(int i = 0;i<S.length;i++){
			if(S[i] == '#')memory++;
			blackNum.add(count);
			count = memory;
		}

		int min = (int) Math.pow(10,10);
		for(int j = 0;j<S.length;j++){
			count = blackNum.get(j) + (whiteNum.get(S.length-1) - whiteNum.get(j));
			min = Math.min(min, count);
		}

		System.out.println(min);

	}

}