less.cc

#include "iostream"
#include <cmath>

int main()
{
  int x, y;
  while (std::cin >> x >> y) {
    if (x < y) {
      std::cout << x << " " << y << std::endl;
    }
    else {
      std::cout << y << " " << x << std::endl;
    }
  }
  return 0;
}