myageapp.js

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

console.log('What\'s your age ? ')
process.stdin.on('data', function (number)  {
   if (!Number(number)) {
      console.log('eh?')
   }
   else if (number < 1) {
      console.log('eh?')
   }   
   else if (number >= 99){
      console.log('Wroooonggg! No way you are older than 99 and know how to use this programm. Try again.');
   }
   else {
      console.log(2018 - number)
   }
   process.exit();
})