Problem:
Score : 300 points

Problem Statement

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.

Sample Input 1

3
#.#

Sample Output 1

1

It is enough to change the color of the first stone to white.

Sample Input 2

5
#.##.

Sample Output 2

2

Sample Input 3

9
.........

Sample Output 3

0

Solution in C (GCC 5.4.1) (judge verdict: Wrong Answer)

#include<stdio.h>
#include<string.h>
int main() {



	char s[200001];
	int  i, n, cnt1 = 0,cnt2=0;

	scanf("%d", &n);
	scanf("%s", s);

	
	if (s[0] == '#') {
		for (i = 0; i < n; i++) {
			if (s[i] == '.')cnt1++;

		}
	}
	else if(s[0]=='.') {
		for (i = 0; s[i]!='#' && i<n; i++) {
			cnt2++;
			
		}
		for (i = cnt2; i < n; i++) {
			if (s[i] == '.')cnt1++;
		}
	}
	
	 printf("%d",cnt1);
	
	return 0;

}