gistfile1.txt

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

console.log('how old are you? ')
process.stdin.on('data', (text) => {
    text = parseInt(text)
    let date = new Date()
    let year = date.getFullYear()
    if (text != NaN && text >= 0 && text <= 99)
        console.log(year - text)
    process.exit()
})