text: /*jshint node:true */
  'use strict';
  
  const stdio = require('stdio');
  const checksum = require('./checksum');
  
  let opts  = stdio.getopt({
    'input': {key: 'i', args: 1, mandatory: true, 'description': 'Puzzle input'},
    'alt': {key: 'a', args: 1, 'description': 'Activate alt progression'},
  });
  
  if (opts.input) {
    console.log(checksum(opts.input, opts.alt));
  }