text: const fs = require("fs");
  const changes = fs.readFileSync(__dirname + "/../input/input_01.txt", "utf8")
    .split("\n")
    .filter(c => c)
    .map(c => parseInt(c, 10));
  const log = new Map([[0, 0]]);
  
  // Part 1
  
  function part1() {
    return changes.reduce((a, c) => a += c, 0);
  }
  
  // Part 2
  
  function part2(shift = 0) {
    for (let i = 0; i < changes.length; i++) {
      shift += changes[i];
      if (log.has(shift)) {
        return shift;
      } else log.set(shift, true);
    }
    return part2(shift);
  }
  
  module.exports = { part1, part2 }
  