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

console.log('How old are you ? ')
process.stdin.on('data', (age) => {

    if (age >= 99) {
        console.log("Enter a number under 100 plizzz.")

    } else if (isNaN(age)) {
        console.log("Enter a number plizzz.")

    } else {
  console.log('You are born in ' + (2019 - age) + '.')
  process.exit()
    }
//   process.exit()
})