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;
int main(){
  int n;cin >> n;
  string s;cin >> s;
  vector<int> b(n+1),w(n+1);
  for(int i=0;i<n;i++){
    if(s[i]=='#'){
      b[i+1]++;
    }
    else{
      w[i]++;
    }
  }
  for(int i=0;i<n;i++){
    b[i+1]+=b[i];
  }
  for(int i=n-1;i>=0;i--){
    w[i]+=w[i+1];
  }
  int ans=1e6;
  for(int i=0;i<=n;i++){
    ans=min(ans,b[i]+w[i]);
  }
  cout << ans << endl;
}