import java.util.*;

class Main {

   public static void main(String[] args) throws Exception {
      Scanner sc = new Scanner(System.in);
      int x = sc.nextInt();
      int y = sc.nextInt();
      int work;
      while (x != 0 || y != 0) {
         if (x > y) {
            work = x;
            x = y;
            y = work;
         }
         System.out.printf("%d %d\n", x, y);
         x = sc.nextInt();
         y = sc.nextInt();
      }
   }
}
/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