import java.util.*;

class Main{
	public static void main(String args[]){
		Scanner sc = new Scanner(System.in);
		int temp, cnt = 0;
		int x[] = new int[3000], y[] = new int[3000];
		
		while(true){
			x[cnt] = sc.nextInt();
			y[cnt] = sc.nextInt();
			
			if(x[cnt] == 0 && y[cnt] == 0)
				break;
			
			if(x[cnt] > y[cnt]){
				temp = x[cnt];
				x[cnt] = y[cnt];
				y[cnt] = temp;
			}
			
			cnt ++;
		}
		
		for(int i = 0; i < cnt; i++)
			System.out.println(x[i] + " " + y[i]);
	}
}
/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