#include <iostream>
#include <vector>
#include <algorithm>

using namespace std;

int main()
{
    int n,m,a;
    long long mo=0;
    vector<int> nek;
    vector<int> mek;
    cin >> n >> m;
    for(int i = 0; i < n-1; i++){
        cin >> a;
        nek.push_back(a);
    }
    sort(nek.rbegin(), nek.rend());
    for(int i = 0; i < m-1; i++){
        cin >> a;
        mek.push_back(a);
    }
    sort(mek.rbegin(), mek.rend());
    int sordb = 1, oszlopdb = 1;
    int holm = 0, holn = 0;
    while(holm < mek.size() || holn < nek.size()){
        if(holm == mek.size() || nek[holn] > mek[holm]){
            mo += nek[holn] * sordb;
            holn++;
            oszlopdb++;
        }else{
            mo += mek[holm] * oszlopdb;
            holm++;
            sordb++;
        }
    }

    cout << mo;

    return 0;
}