'use strict'

const Main = (input) => {
  const tmp = input.trim().split('\n')
  const K = parseInt(tmp[0])
  const S = tmp[1]

  let result = ''

  if (S.length <= K) {
    result = S
  } else {
    result=S.substr(0, K) + "..."
  }

  console.log(result)
  return result
}

Main(require('fs').readFileSync('/dev/stdin', 'utf8'))