#include <iostream>
#include <string>

void countingSort(int* numbers, int array_size)
{
    int max = 1;
    int min = 0;
    int k = max - min + 1;
    int* c = new int[k];
    int* b = new int[array_size];
    for (int i = 0; i < k; ++i)
        c[i] = 0;

    for (int i = 0; i < array_size; ++i)
        c[numbers[i] - min]++;

    for (int j = 1; j < k; ++j)
        c[j] = c[j] + c[j - 1];

    for (int i = array_size - 1; i >= 0; --i)
    {
        c[numbers[i] - min]--;
        b[c[numbers[i] - min]] = numbers[i];
    }
    delete[] c;

    for (int i = 0; i < array_size; i++)
        numbers[i] = b[i];
    delete[] b;
}

int main()
{
    int n, x;
    std::string numbers;
    std::cin >> n;
    int* arr = new int[n];
    std::cin >> numbers;
    for (int i = 0; i < n; ++i)
        arr[i] = numbers[i] - 48;

    countingSort(arr, n);
    for (int i = 0; i < n; ++i)
        std::cout << arr[i];

    delete[] arr;
    return 0;
}