Problem:
Score : 200 points

Problem Statement

You are given a string S of length N consisting of lowercase English letters, and an integer K.
Print the string obtained by replacing every character in S that differs from the K-th character of S, with *.

Constraints

1 \leq K \leq N\leq 10

S is a string of length N consisting of lowercase English letters.

N and K are integers.

Input

Input is given from Standard Input in the following format:

N
S
K

Output

Print the string obtained by replacing every character in S that differs from the K-th character of S, with *.

Sample Input 1

5
error
2

Sample Output 1

*rr*r

The second character of S is r. When we replace every character in error that differs from r with *, we get the string *rr*r.

Sample Input 2

6
eleven
5

Sample Output 2

e*e*e*

Sample Input 3

9
education
7

Sample Output 3

******i**

Solution in C++14 (GCC 5.4.1) (judge verdict: Accepted)

#include <iostream>
#include <vector>
#include <algorithm>

#define REP(i, n) for(int i = 0; i < n; i++)

using namespace std;

int main(){
	int n,k;
    string s;
	cin>>n>>s>>k;
	
    char target = s[k-1];

	string result;
    REP(i,n){
        if( s[i] != target ){
            result += "*";
        }
        else{
            result += s[i];
        }
    }

    cout << result << endl;
	
	return 0;
}