import java.util.Scanner;

class Main {
	public static void main(String[] args) throws Exception {
		Scanner sc = new Scanner(System.in);
		StringBuilder sb = new StringBuilder();
		while(true){
			int x=sc.nextInt();
			int y=sc.nextInt();
			if(x==0&&y==0){
				break;
			}else if(x>y){
	        	sb.append(y+" "+x+"\n");
	        }else{
	        	sb.append(x+" "+y+"\n");
	        }
		}
		System.out.print(sb);
	}
}
/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