1038

#include<iostream>
#include<string>
#include<vector>
#include<algorithm>
using namespace std;
bool cmp(string a, string b) { return a + b < b + a; }
int main()
{


		int n;
		cin >> n;
		vector<string> Num;
		bool flag = false;
		for (int i = 0; i < n; i++)
		{
			string num;
			cin >> num;
			//num += num[0];
			Num.push_back(num);
		}
		sort(Num.begin(), Num.end(), cmp);
		
		for (int i = 0; i < n; i++)
		{
			//Num[i].pop_back();
			if (!flag)
			{
				int j = 0;
				while (Num[i][j] == '0')
					j++;
				while (j < Num[i].length())
				{
					cout << Num[i][j++];
					flag = true;
				}

			}
			else
			{
				cout << Num[i];
				flag = true;
			}
		}
		if (!flag)
			cout << 0;
		cout << endl;
	system("pause");
	return 0;
}