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

console.log('What\'s your age ? ')
process.stdin.on('data', (text) => {
  text = parseInt(text, 10);
  if (typeof text === 'number' && text < 100 && text > 0) {
    const birthYear = 2019 - text;
    console.log(`Your date of birth is ${birthYear}`);
  } else {
    console.log(`The age must be a number & less than a hundred`);
  }
  process.exit()
});