import java.util.Scanner;

/**
 * @author kawakami
 
*/
class Main {

	/**
	 * @param args
	 */
	public static void main(String[] args) {
		// TODO Auto-generated method stub
		Scanner as = new Scanner(System.in);
	       
        int x;
        int y;

       
           
           x = as.nextInt();
           y = as.nextInt();
           
           if(x<y){
               System.out.println(x+" "+y);

              }
            else{
               System.out.println(y+" "+x);

              } 
           
           
           

        while(true){
           
           
           x = as.nextInt();
           y = as.nextInt();
           if(x==0 && y==0){
               break;
  }
           
           
           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