import java.io.*;

class Main{
	
	public static void main(String[] args)throws IOException{
		
		BufferedReader input = new BufferedReader(new InputStreamReader(System.in));
		StringBuilder result = new StringBuilder();
		
		while(true){
			String tmp = input.readLine();
			String[] strInput = tmp.split(" ");
			int x = Integer.parseInt(strInput[0]);
			int y = Integer.parseInt(strInput[1]);
			
			if(x == 0 && y == 0){
				break;
			}
			
			if(x > y){
			    int temp = x;
			    x = y;
			    y = temp;
			   
			}

			result.append(x + " " + y + "\n");
		}
	       
		System.out.print(result);
		
	}
	
}
/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