import java.io.*;

public class Main {
    public static void main(String... args) throws IOException {
        final BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        final StringBuilder sb = new StringBuilder();
        while (true) {
            final String line = br.readLine();
            final int index = line.indexOf(" ");
            final int x = Integer.parseInt(line.substring(0, index));
            final int y = Integer.parseInt(line.substring(index+1, line.length()));
            if (x == 0 && y == 0) break;
            sb.append(x < y ? x + " " + y : y + " " + x).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