#include <iostream>
#include <string>
int main() {
	int N;
	std::cin >> N;
	std::string* S = new std::string[N];
	std::string Answer;
	for (int i = 0; i < N; i++) {
		std::cin >> S[i];
	}
	for (int i = 0; i < N; i++) {
		Answer+= S[i];
	}
	std::cout << Answer << std::endl;
	return 0;
}