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

console.log('What\'s your age ? ')
process.stdin.on('data', (age) => {

 if((0>=age||age>99)||(isNaN(age))) {
      console.log ("invalid data")
    }
    else {
  console.log('You was born in ' + (2019 - age))}
  process.exit()
})