#include <iostream>
#include <algorithm>
#include <string>
#include <vector>

int main() {
	std::vector<std::string> s(3);
	for (int i = 0; i < 3; i++) {
		std::cin >> s[i];
	}
	std::sort(s.begin(), s.end());
	std::cout << s[1] << std::endl;
}