Merging maps with Semigroups

import scala.io.Source
import cats.implicits._

object Temp extends App {
  val ru = load("/home/mitrakov/buffer/ru.txt")
  val en = load("/home/mitrakov/buffer/en.txt")
  val pt = load("/home/mitrakov/buffer/pt.txt")

  val all = ru.mapValues(List(_)) |+| en.mapValues(List(_)) |+| pt.mapValues(List(_))
  val result = all.mapValues(_.size).toList.sortBy(_._2)

  result foreach println

  def load(filename: String): Map[String, String] = {
    Source.fromFile(filename).getLines().map { line =>
      line.trim.split(":").toList match {
        case head :: tail => head -> tail.mkString(":")
      }
    }.toMap
  }
}