function Main(input) {
  input = input.replace(/\n/g, ' ');
  input = input.split(" ");
  var A = input[0];
  var B = input[1];
  var ans  = "";
  if(A < B.length){
    ans += B.slice(0,A) + "...";
  }else{
    ans=B;
  }
  console.log(ans);
}
Main(require("fs").readFileSync("/dev/stdin", "utf8"));