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 str = new StringBuilder();
        String[] data;
        int x, y;
        while (true) {
            data = br.readLine().split(" ");
            x = Integer.parseInt(data[0]);
            y = Integer.parseInt(data[1]);
            if (x == 0 && y == 0) {
                break;
            }
            if (x < y) {
                str.append(data[0]).append(" ").append(data[1]).append("\n");
            } else {
                str.append(data[1]).append(" ").append(data[0]).append("\n");
            }
        }
        System.out.print(str);
    }
}
/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