const Main = input => {
  const inputParsed = input.split("\n");
  const number = Number(inputParsed[0]);
  if(inputParsed[1].length > number){
    console.log(inputParsed[1].substring(0,number) + '...')
  }else{
    console.log(inputParsed[1])
  }
}
 
Main(require("fs").readFileSync("/dev/stdin", "utf8"));