import java.util.Scanner;

class Main{
  public static void main(String args[]){
    Scanner sc = new Scanner(System.in);
    while(true){
      int x = sc.nextInt();
      int y = sc.nextInt();
      if(x == 0 && y == 0){
        break;
      }else if(x <= y){
        System.out.println(x+" "+y);
      }else{
        System.out.println(y+" "+x);
      }
    }
  }
}


/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