import java.util.Scanner;
class Main {
	
	public static void main(String[] args) {
		Scanner scanner = new Scanner(System.in);
		
		for (int num = 1;; num++ ){
			int numx = scanner.nextInt();
			int numy = scanner.nextInt();
			
			if(numx == 0 && numy == 0){
				break;
			}		    
				else if(numx < numy){
					System.out.println(numx+" "+numy);
				}
				else {
					System.out.println(numy+" "+numx);
				}
	    	}
	}	

}
/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