import java.util.Scanner;
public class Main {
    public static void main (String args[]){
    	Scanner str =new Scanner(System.in);
        StringBuffer buf = new StringBuffer();
    	while(true){
    	    int a = str.nextInt();
    	    int b = str.nextInt();
    	    if(a==0&&b==0){
    	    	break;
    	    }
    	    if(a<b){
    	        buf.append(Integer.toString(a)).append(" ").append(Integer.toString(b)).append("\n");
    	    }
    	    if(a>b){
    	    	buf.append(Integer.toString(b)).append(" ").append(Integer.toString(a)).append("\n");
    	    }
    	    if(a==b){
    	    	buf.append(Integer.toString(b)).append(" ").append(Integer.toString(a)).append("\n");
    	    }

    	}
    	System.out.print(buf);
    }
}
/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