import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.StringTokenizer;


public class Main {
    public static void main(String[] args) {

    	try{
    		InputStreamReader isr = new InputStreamReader(System.in);
			BufferedReader br = new BufferedReader(isr);
			while(true){
				String buf = br.readLine();
				StringTokenizer st=new StringTokenizer(buf," ");
	    		int x = Integer.parseInt(st.nextToken());
	    		int y = Integer.parseInt(st.nextToken());
				if(x == 0 && y==0) break;
				if(x > y){
					int storage=y;
					y=x;
					x=storage;
				}
				System.out.println(x+" "+y);
    		}

    	} catch(IOException e) {
    		System.err.println(e);
		}
    }
}
/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