HDU 1412 {A} + {B}

#include<iostream>
#include<cstdio>
#include<cstring>
#include<algorithm>
#include<limits.h>
#include<list>
using namespace std;

int main()
{
    int n,m,x;
    list<int>s1;
    list<int>s2;
    while(cin>>n>>m)
    {
        for(int i=0;i<n;i++)
        {
            cin>>x;
            s1.push_back(x);
        }
        for(int i=0;i<m;i++)
        {
            cin>>x;
            s2.push_back(x);
        }
        s1.merge(s2);
        s1.sort();
        s1.unique();
        int cnt=0;
        while(!s1.empty())
        {
           if(!cnt)
                cout<<s1.front();
           else
                cout<<" "<<s1.front();
           cnt=1;
           s1.pop_front();
        }
        cout<<endl;
    }
    return 0;
}