#include <iostream>
#include <algorithm>
using namespace std;

int main() {
	int n;
	long a[5000];
	cin >> n;
	for (int i = 0; i < n; i++)cin >> a[i];
	sort(a, a + 5000);
	for (int i = 0; i < n; i++)cout << a[i];
	return 0;
}