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;

  int w = 0;
  int b = 0;

  for(int i=0;i<n;i++) {
    if(s[i] == '.') w++;
    else b++;
  }

  int ans = w;

  int now = w;

  for(int i=0;i<n;i++) {
    if(s[i] == '.') {
      now--;
      if(now < ans) ans = now;
    }
    else {
      now++;
    }
  }

  cout << ans << endl;
}