var input = ""
process.stdin.resume();
process.stdin.setEncoding('utf-8');
process.stdin.on('data', function(chunk) {
  input += chunk;
});

process.stdin.on('end', function() {
  input = input.split("\n");
  i = 0
  while (input[i] != 0) {
    arr = input[i].split(" ")
    if (arr[0] != 0 || arr[1] != 0) {
      arr.sort();
      console.log(arr[0] + " " +  arr[1]);
    }
    i++;
  }
});