val seenVertices = mutable.HashMap[Int, Int]()

    var bitMasks = for (i <- 0 to 24; j <- 0 to 24) yield (1 << i | 1 << j)
    bitMasks = 0 +: bitMasks

    val bufferedSource = Source.fromFile("/home/asznajder/Coursera/clustering_big.txt")
    val lines = bufferedSource.getLines()

    val uf = UnionFind(lines.next().split(" ")(0).toInt)
    for ((line, id) <- lines.zipWithIndex) {
      val code = Integer.parseInt(line.replaceAll(" ", ""), 2)
      for (mask <- bitMasks) {
        val modifiedCode = code ^ mask
        seenVertices.get(modifiedCode) match {
          case Some(seen_id) => uf.union(id, seen_id)
          case None => {
            seenVertices(code) = id
          }
        }
      }
    }
    bufferedSource.close()