hdu1412

/**/
#include <cstdio>
#include <cstring>
#include <cmath>
#include <cctype>
#include <iostream>
#include <algorithm>
#include <map>
#include <set>
#include <vector>
#include <string>
#include <stack>
#include <queue>

typedef long long LL;
using namespace std;

int n, m;

int main()
{
	//freopen("in.txt", "r", stdin);
	//freopen("out.txt", "w", stdout);

	while(scanf("%d %d", &n, &m) == 2){
		set<int>st;
		int x;
		for (int i = 1; i <= n; i++){
			scanf("%d", &x);
			st.insert(x);
		}
		for (int i = 1; i <= m; i++){
			scanf("%d", &x);
			st.insert(x);
		}

		set<int>::iterator it = st.begin();
		int flag = 0;
		for (; it != st.end(); it++){
			if(!flag){
				printf("%d", *it);
				flag = 1;
			}else{
				printf(" %d", *it);
			}
		}
		printf("\n");
	}

	return 0;
}
/**/