#include <bits/stdc++.h>

using namespace std;

set<int> a;

int b[];

int main()

{

    int n, m;

    int i, j;

    while (~scanf("%d %d", &n, &m))

    {

        for (i = ; i < n + m; i++)

        {

            int x;

            scanf("%d", &x);

            a.insert(x);

        }

        // sort (a.begin(),a.end());

        int q = ;

        memset(b,,sizeof(b));

        for (set<int>::iterator it = a.begin() ; it != a.end(); it++)

        {

            b[q] = *it;

            q++;

        }

        for (int i = ; i < q; i++)

        {

            if (i == q - )

            {

                cout << b[i];

            }

            else

            {

                cout << b[i] << " ";

            }

        }

        cout << endl;

        a.clear();

    }

    return ;

}