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

console.log('How old are you ? ')
process.stdin.on('data', (birthday) => {
    if (!isNaN(birthday) && birthday < 99) {
        console.log('Your year of birth is ' + (2018 - birthday))
        process.exit()
    } else {
        console.log('Please enter your real age');
        process.exit()
    }
})