const input = "kglvqrro";

var moveTypes = {
  U: [0, -1],
  D: [0, 1],
  L: [-1, 0],
  R: [1, 0],
}

md5 = (str)=>{
  var md5sum = require("crypto").createHash("md5");
  md5sum.update(str);
  return md5sum.digest("hex");
}

doorOpen = (path, pos)=>(Boolean(md5(input + path)[pos].match(/[bcdef]/)));

getCoords = (path)=>(path.split("").map((dir)=>(moveTypes[dir]))).reduce((coord, displacement)=>(coord.map((a, i)=>(a + displacement[i]))), [0, 0]);

getNextPath = (path)=>{
  [x, y] = getCoords(path);
  var paths = [];
  if(y > 0){
    if(doorOpen(path, 0)){
      paths.push(path + "U");
    }
  }
  if(y < 3){
    if(doorOpen(path, 1)){
      paths.push(path + "D");
    }
  }
  if(x > 0){
    if(doorOpen(path, 2)){
      paths.push(path + "L");
    }
  }
  if(x < 3){
    if(doorOpen(path, 3)){
      paths.push(path + "R");
    }
  }
  return paths;
}

var paths = [""];
while(paths.map(getCoords).filter(([x, y])=>((x == 3) && (y == 3))).length == 0){
  var newpaths = []
  for(var path of paths){
    newpaths = newpaths.concat(getNextPath(path));
  }
  paths = newpaths;
}

console.log(paths.filter((path)=>(getCoords(path).filter((i)=>(i == 3)).length == 2))[0]);
//console.log(getNextPath(""));