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

public class Main {

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

		for(;;) {
			String num = br.readLine();
			String[] set = num.split(" ");

			int a = Integer.parseInt(set[0]);
			int b = Integer.parseInt(set[1]);

			if (a == 0 && b == 0) {
				break;
			} else if (a > b) {
			sb.append(b).append(" ").append(a).append("\n");
			} else {
			sb.append(a).append(" ").append(b).append("\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