text: #!/usr/bin/env node
  
  const argv = require('yargs').argv;
  
  function run( limit ) {
  	let sequence = buildFibSequence( limit );
  	return sequence.reduce(function(sum, value) {
  		return sum + ((value % 2 === 0) ? value : 0);
  	}, 0);
  }
  
  function buildFibSequence( limit, carry=[1,2] ) {
  	let nextTerm = (carry[carry.length-1]||0) + (carry[carry.length-2]||0);
  	return (nextTerm > limit) ? carry : buildFibSequence( limit, [...carry, nextTerm] );
  }
  
  if (argv.limit) {
  	console.log(run(argv.limit));
  }
  
  export { run }