import java.util.Scanner;

public class Main{
  public static void main(String[] args){
    Scanner scan = new Scanner(System.in);
    while(true){
    int x = scan.nextInt();
    int y = scan.nextInt();
    if( x == 0 && y == 0 )break;
    if( x > y ){
    System.out.println(""+y+" "+x+"");
    }else{
    System.out.println(""+x+" "+y+"");
    }     
   }
  }
}
/tmp/hf-datasets-cache/medium/datasets/42704881117311-config-parquet-and-info-qiankunmu-Project_CodeNet-896c9d36/hub/datasets--qiankunmu--Project_CodeNet_Python800_and_Java250/snapshots/c899fde44a77ba1cc14973ed3de064e4ff3aadc7/Project_CodeNet_Java250.tar.gz