//No.597 concat
#include<iostream>
#include<string>
using namespace std;
int main()
{
	
	string S,tmp_S;
	int N;
	cin >> N;
	for (int i = 0; i < N; i++) {
		cin >> tmp_S;
		S += tmp_S;
	}
	cout << S;
	
	return 0;
}