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 CPP):

Solution:
#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
int n,ans=1e8,sum1,sum2;
string s;
int main(){
	cin >> n >> s;
	for(int i=0;i<n;i++)
		if(s[i]=='.')sum2++;
	ans=min(ans,sum2);
	for(int i=0;i<n;i++){
		if(s[i]=='#')sum1++;
		if(s[i]=='.')sum2--;
		ans=min(ans,sum1+sum2);
	}
	cout << ans;
    return 0;
}