import java.util.Scanner;

class MaxNum {

    public int[] arr;

    public void GetMaxNum() {
        char[][] numArr = new char[arr.length][];
        for (int i = 0; i < arr.length; i++) {
            numArr[i] = ("" + arr[i]).toCharArray();
        }
        QuickSort(arr.length, numArr);
        for (int i = 0; i < arr.length; i++) {
            System.out.print(numArr[i]);
        }
    }

    public void QuickSort(int n, char[][] arr) {
        QuickSortRec(0, n - 1, arr);
    }

    public void QuickSortRec(int low, int high, char[][] arr) {
        if (low < high) {
            int q = Partition(low, high, arr);
            QuickSortRec(low, q - 1, arr);
            QuickSortRec(q + 1, high, arr);

        }

    }

    public int Partition(int low, int high, char[][] arr) {
        int i = low;
        int j = low;
        while (j < high) {
            int k = 0;
            while (arr[j].length > k && arr[high].length > k) {
                if (arr[j][k] > arr[high][k]) {
                        char[] t = arr[i];
                        arr[i] = new char[arr[j].length];
                        arr[i] = arr[j];
                        arr[j] = new char[t.length];
                        arr[j] = t;
                        i++;
                        break;
                } else {
                    if(arr[j][k] < arr[high][k]) {
                        break;
                    }
                }
                if ((arr[j].length == k+1 || arr[high].length == k+1) && ((int) arr[j][k] - (int) '0' == (int) arr[high][k] - (int) '0')
                        && ((arr[high].length == (k + 1)
                        && arr[j].length > arr[high].length && arr[j][k + 1] != '0') || (arr[j].length == (k + 1)
                        && arr[high].length > arr[j].length && arr[high][k + 1] == '0')))
                {
                    char[] t = arr[i];
                    arr[i] = new char[arr[j].length];
                    arr[i] = arr[j];
                    arr[j] = new char[t.length];
                    arr[j] = t;
                    i++;
                    break;
                }
                k++;
            }
            j++;
        }

        char[] t = arr[i];
        arr[i] = new char[arr[high].length];
        arr[i] = arr[high];
        arr[high] = new char[t.length];
        arr[high] = t;
        return i;
    }
    public static void main(String[] args) {
        MaxNum p = new MaxNum();
        Scanner in = new Scanner(System.in);
        int n = in.nextInt();
        p.arr = new int[n];
        for (int i = 0; i < n; i++) {
            p.arr[i] = in.nextInt();
        }
        p.GetMaxNum();
    }
}