object Problem280 {

  def proc(z: List[Long]) = {
    val child = z.head
    val parent = z.last

    // 1/(child/parent) なので parent/child を表示
    parent + "/" + child
  }

  def main(args: Array[String]) {
    //  N
    //  z1 z2 ... zN
    val N = scala.io.StdIn.readInt()
    val z = scala.io.StdIn.readLine().split(" ").map(_.toLong).toList

    val result = proc(z)
    println(result)
  }

  def test = {
    assert(proc(List(20, 40)) == "2/1")
    assert(proc(List(10, 10, 10)) == "1/1")
    assert(proc(List(20, 60)) == "3/1")
  }
}