#include<iostream>
#include<algorithm>
#include <vector>
#include<cmath>
using namespace std;
typedef long long int lont;
int main() {
	int N;
	cin >> N;
	vector<string>vec(N);
	for (int ia = 0; ia < N; ia++) {
		cin >> vec.at(ia);
	}
	for (int ib = 0; ib < N; ib++) {
		cout << vec.at(ib);
	}
	cout << endl;
}