import scala.io.StdIn.readLine

object Main {
	def main(args: Array[String])={
		var checkSorted: Unit={
			val i = readLine()
			if(i != "0 0"){
				println(i.split(" ").map(_.toInt).sorted.mkString(" "))
				checkSorted
			}
		}
		checkSorted
	}
}