#include<iostream>
#include<cstdio>
#include<cmath>
#include<cstring>
#include<cstdlib>
#include<algorithm>
#define ll long long
#define N 25003
using namespace std;
inline int read(int &ret)
{
	ret=0;char ch=getchar();
	while(ch<'0'||ch>'9') ch=getchar();
	while('0'<=ch&&ch<='9')
	{
		ret=ret*10-'0'+ch;
		ch=getchar();
	}
}
int n,m,a[N],b[N];
int main()
{
	//freopen("spicychicken.in","r",stdin);
	//freopen("spicychicken.out","w",stdout);
	read(a[0]);read(b[0]);read(n);read(m);
	for(int i=n;i;--i)read(a[i]);
	sort(a,a+n+1,greater<int>());
	for(int i=0;i<=n;++i)a[i]=a[i]-a[i+1];
	sort(a,a+n+1);
	for(int i=m;i;--i)read(b[i]);
	sort(b,b+m+1,greater<int>());
	for(int i=0;i<=m;++i)b[i]=b[i]-b[i+1];
	sort(b,b+m+1);
	int p=1,q=1;
	ll ans=(ll)a[0]*m+(ll)b[0]*n;
	while(p<=n&&q<=m)
		if(a[p]<b[q])ans+=(ll)a[p++]*(m-q+1);
		else ans+=(ll)b[q++]*(n-p+1);
	printf("%lld\n",ans);
	return 0;
}