import java.util.*;
public class Main{
public static void main(String[] args){
Scanner sc = new Scanner(System.in);
int i=0;
for(;;){
int a=sc.nextInt();
int b=sc.nextInt();
if(a==0 && b==0)break;
if(a>b){i=a;a=b;b=i;}
System.out.println(a+" "+b);}}}
/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