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.util.Scanner;
class Main{
	public static void main(String args[]) {
		Scanner sc = new Scanner(System.in);
		int N = sc.nextInt();
		String S = sc.next();
		sc.close();
		int BLACK = 0;
		int WHITE = 0;
		for(int i=0;i<N;i++) {
			if(S.charAt(i)=='.') {
				WHITE++;
			}
		}
		int min = WHITE;
		for(int i=0;i<N;i++) {
			if(S.charAt(i)=='#') {
				BLACK++;
			}
			else {
				WHITE--;
			}

			min = Math.min(min, WHITE + BLACK);
		}
		System.out.println(min);
	}
}