function main(arg) {
    var args = arg.split('\n');
    var N = +args[0];
    var S = args[1];
    var K = +args[2];
 
    var tg = S[K];
  
    var arr = [...S].map(function(c){
        if(c !== tg) return '*'
        else return c
    }).join('')
 
    console.log(arr)
}
main(require('fs').readFileSync('/dev/stdin', 'utf8'));