gistfile1.txt

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

console.log('How old are you? ')
process.stdin.on(('data', (text) => {
            if (text == number && text >= 0 && text <= 99) {
                console.log(2018 - text)
            } else {
                console.log('not valid')
            }
        })