import java.util.Scanner;

public class Main{
    public static void main(String[] args){
	Scanner stdin = new Scanner(System.in);
	int x = stdin.nextInt();
	int y = stdin.nextInt();
        int w = 0;
	if(y<x){
	    w = y;
	    y = x;
	    x = w;
	}
	while(x!=0 || y!=0){
	    System.out.println(x+" "+y);
	    x = stdin.nextInt();
	    y = stdin.nextInt();
	    if(y<x){
		w = y;
		y = x;
		x = w;
	    }
	}
    }
}

	
/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