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

console.log('How old are you ?')
process.stdin.on('data', (text) => {
    if (text >= 1 && text <= 99) {
        console.log(`You were born in ${2019 - text}`)
    }
    else  {
        console.log(`error : must be a number between 1 and 99`)
    }
    process.exit()
})