#include<bits/stdc++.h>
using namespace std;
bool cmp(int a,int s){
	return a<s;
}
int main()
{
	int m,n,i,s=0,a[1000],b[1000],c[2000],d[2000];
	cin>>m>>n;
	for(i=0;i<m;i++){
		cin>>a[i];
		c[i]=a[i];
	}
	for(i=0;i<n;i++){
		cin>>b[i];
		c[i+m]=b[i];
	}
	s=0;
	sort(c,c+m+n,cmp);
	for(i=0;i<m+n;i++){
		if(c[i]!=c[i+1]){
			d[s]=c[i];
			s++;
		}
	}
	for(i=0;i<s;i++){
		cout<<d[i]<<" ";
	}
	cout<<endl;
	s=0;
	for(i=0;i<m+n;i++){
		if(c[i]==c[i+1]){
			d[s]=c[i];
			s++;
		}
	}
	for(i=0;i<s;i++){
		cout<<d[i]<<" ";
	}
	cout<<endl;
	return 0;
}

/**************************************************************
	Problem: 1471
	User: zzz
	Language: C++
	Result: Accepted
	Time:15 ms
	Memory:2076 kb
****************************************************************/