process.stdin.resume()
process.stdin.setEncoding('utf8')

console.log('How old are you')
process.stdin.on('data', (number) => {
  if (typeof number != "NaN"){
        if (number > 0 && number < 99){
          console.log(2019 - number)
        }else{
          console.log('You must enter a number equal or less than 99!', (number))
        }

  }else {
    console.log('You must enter a number!', (number))
  }
  process.exit()
})