function Main(input) {
  var args = input.split('\n');
  var n = parseInt(args.shift());
  var s = args.shift();
  var k = parseInt(args.shift());

  var kstr = s.charAt(k - 1);
  var ret = s.replace(new RegExp('[^' + kstr + ']', 'g'), '*');

  console.log(ret);

}

Main(require("fs").readFileSync("/dev/stdin", "utf8"));