#include <iostream>
#include <stack>
#include <cstring>
#include <cstdio>
#include <string>
#include <algorithm>
#include <queue>
#include <set>

using namespace std;
/**/
#define ms(arr, val) memset(arr, val, sizeof(arr))
#define N 10005
#define INF 0x3fffffff
#define vint vector<int>
#define sint set<int>

sint s;
int main()
{
    int  n, m;
    int t;
    while (cin >> n >> m)
    {
        s.clear();
        for (int i = 0; i < n + m; i++)
        {
            cin >> t;
            s.insert(t);
        }

        for (sint::iterator it = s.begin(); it != --s.end(); it++)
        {
            cout << *it <<‘ ‘;
        }
        cout << *(--s.end()) << endl;
    }
    return 0;
}