function main(input) {
  const s = input.split(/\n/)
  
  const n1 = s[1]
  const n2 = parseInt(s[2], 10) - 1
  
  const t = n1[n2]
  
  console.log([].slice.call(n1).map(s => s === t ? s : "*").join(""))
}

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