#include <iostream>
#include <set>
#include <cstring>
#include <algorithm>

using namespace std;

int main()
{
    set<int> A;
    int n,m;
    cin>>n>>m;
    n=n+m;
    while(n--)
    {
        cin>>m;
       A.insert(m); 
    }
    set<int>::iterator it;
    it=A.begin();
    cout<<*it;
    for(++it;it!=A.end();++it)
    {
        cout<<" "<<*it;
    }
    return 0;
}