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

class Main {
    public static void main(String[] args) throws IOException {
    	BufferedReader br = new BufferedReader(new InputStreamReader(System.in));

        while(true){
        	String strArr[] = br.readLine().split(" ");
            int a=Integer.parseInt(strArr[0]);
            int b=Integer.parseInt(strArr[1]);

            if(a==0 && b== 0){
            	break;
            }
            else if(b<a){
            	int c=a;
            	a=b;
            	b=c;
            }
            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