function Main(input) {
  lines = input.split('\n');
  n = lines[0]
  s = lines[1]
  k = lines[2]
  c = s[k-1]
  re = new RegExp('[^' + c + ']', 'g')
  console.log(s.replace(re,'*'))
}
Main(require("fs").readFileSync("/dev/stdin", "utf8"));
