#include <iostream>
#include <string>
using namespace std;
int main()
{
    int n;
    long long a[20] = {0};
    cin >> n;
    string as[n], a0[n];
    for (int i = 1; i <= n; i++)
    {
        int s;
        cin >> s;
        a[i] = s;
        a0[i] = to_string(a[i]);// 使as字符串为“整形”
        a[i] = s * 10;
        as[i] = to_string(a[i]); // 使as字符串为“整形+0”
    }
    
    string t = as[1];//初始化比较字符串
    int record = 1;//初始化比较记录数
    string sum = "";//初始化输出
    

    for (int j = 1; j <= n; j++)//进行n次操作
    {
        for (int k = 1; k <= n; k++)
        {
            for (int y = 0; y <= (size(t) - 1); y++)
            {
                if (as[k][y] > t[y])
                {
                    t = as[k];
                    record = k;
                    break;
                }
                else if (as[k][y] < t[y])
                {
                    break;
                }
            }
        }
        sum = sum + a0[record];
        t = "0";
        as[record] = "0";
    }
    cout << sum;
    return 0;
}