HackerRank Javascript stdin using an ES6 generator and larger buffer

readfile.js.es6

'use strict';

function* readLine(stream) {
  const EOL = require('os').EOL;
  const Fs = require('fs');
  const buf = new Buffer(1024);

  stream.resume();
  stream.setEncoding('ascii');

  while (Fs.readSync(stream.fd, buf, 0, buf.length)) {
    let lines = buf.toString().split(EOL);
    if (lines.length < 1) {
      break;
    }

    for (let index in lines) {
      yield lines[index];
    }
  }
}

let reader = readLine(process.stdin);
let a = parseInt(reader.next().value);
let b = parseInt(reader.next().value);

console.log(a+b)