import java.io.*;
 
class Main {
    public static void main(String[] args) throws IOException {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        StringBuilder output = new StringBuilder();
        while(true) {
            String str = br.readLine();
            if(str.equals("0 0")) break;
            int x = Integer.parseInt(str.substring(0, str.indexOf(' ')));
            int y = Integer.parseInt(str.substring(str.indexOf(' ')+1));
            if(x<=y) output.append(x+" "+y+"\n");
            else output.append(y+" "+x+"\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