import java.io.*;

class Main{
 public static void main(String[] args)throws IOException{
  int x,y;
  BufferedReader br=new BufferedReader(new InputStreamReader(System.in));
  
  
  
  while(true){
    String str = br.readLine(); 
    String[] strAry = str.split(" ");
    x = Integer.parseInt(strAry[0]);  
    y = Integer.parseInt(strAry[1]);   
    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