// parameter "input" gets all data
function Main(input) {
 // the first line is assigned to input[0], the second line is assigned to input[1] similarly.
 input = input.split("\n");
 // convert string from integer using "parseInt"
 var s = parseInt(input[0], 10);
 var k = input[1] 
 var ans
  if (s>=k.length){
    ans=k
  } else {
    ans=k.substr(0,s)+'...'
  }
 //output
 console.log(ans)
}
// Don't edit this line!
Main(require("fs").readFileSync("/dev/stdin", "utf8"));
