#include<iostream>
#include<algorithm>
using namespace std;

const int MAXN = 1e4 + 5;
struct node{
	int val, id;
}p[MAXN * 2];
int n, m;

int main(){
	freopen("chocolate.in", "r", stdin);
	freopen("chocolate.out", "w", stdout);
	cin >> n >> m;
	for(int i = 1;i < n;i ++){
		cin >> p[i].val;
		p[i].id = 1;
	}
	for(int i = n;i < n + m - 1;i ++){
		cin >> p[i].val;
		p[i].id = 2;
	}
	sort(p + 1, p + n + m - 1, [](node x, node y){
		return x.val > y.val;
	});
	int h = 1, s = 1, ans = 0;
	for(int i = 1;i < n + m - 1;i ++){
		if(p[i].id == 1){
			ans += (p[i].val * s);
			h ++;
		}
		else{
			ans += (p[i].val * h);
			s ++;
		}
	}
	cout << ans << '\n';
	return 0;
}