#include <iostream>
#include <set>

int main() {
    int n, m;
    std::set<int> unionSet;

    // Input first array
    std::cin >> n;
    for (int i = 0; i < n; ++i) {
        int num;
        std::cin >> num;
        unionSet.insert(num);
    }

    // Input second array
    std::cin >> m;
    for (int i = 0; i < m; ++i) {
        int num;
        std::cin >> num;
        unionSet.insert(num);
    }

    // Output union in ascending order
    for (int num : unionSet) {
        std::cout << num;
    }
    std::cout << std::endl;

    return 0;
}