import java.util.Scanner;

public class Main {
	public static void main(String[] args) {
		StringBuilder output = new StringBuilder();
		Scanner scan = new Scanner(System.in);
		while(true) {
			int a = scan.nextInt();
			int b = scan.nextInt();
			if (a == 0 && b == 0)
				break;
			if (a <= b) {
				output.append(a).append(" ").append(b).append('\n');
			} else {
				output.append(b).append(" ").append(a).append('\n');
			}
		}
		System.out.print(output);
	}
}
/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