#include <iostream>
	#include <set>
	#include <sstream>

	int main()
	{
		std::string line;
		while(std::getline(std::cin, line))
		{
			std::stringstream ss(line);
			std::string number;
			std::set<std::string> numbers;
			while(ss >> number)
				numbers.insert(number);
			for(const auto& n: numbers)
				std::cout << n;
			std::cout << ' ';
			for(auto it = numbers.rbegin(); it != numbers.rend(); it++)
				std::cout << *it;
			std::cout << std::endl;
		}
	}