def urbanmain() = {

  import M5a._

  import scala.concurrent._

  import scala.concurrent.duration._

  import ExecutionContext.Implicits.global

  import scala.language.postfixOps 

  lazy val f = Future {

    assert(run("[-]", Map(0 -> 100)) == Map(0 -> 0))

    assert(run("[->+<]", Map(0 -> 10)) == Map(0 -> 0, 1 -> 10))

    assert(run("[>>+>>+<<<<-]", Map(0 -> 42)) == Map(0 -> 0, 2 -> 42, 4 -> 42))

    val hw_urban = """+++++[->++++++++++<]>--<+++[->>++++++++++

    assert(run(hw_urban) == Map(0 -> 0, 1 -> 58, 2 -> 32))

    val hw_urban1 = """++++++++[>++++[>++>+++>+++>+<<<<-]>+>+>->>+[<]<-]>>.>---.

    assert(run(hw_urban1) == Map(0 -> 0, 5 -> 33, 1 -> 0, 6 -> 10, 2 -> 72, 3 -> 100, 4 -> 87))

  }

  Await.result(f, 32 second)