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

console.log('What\'s your age ? ')
process.stdin.on('data', (number) => {
    if (number >= 100) {
        console.log('Please enter an age below 100');
        process.exit();
    };

    if (isNaN(number)) {
        console.log('Please enter a number, up to 99');
        process.exit();
    }

    let birthYear = 2019-number;
    console.log('You were likely born in ' + birthYear);
    process.exit()
})