#include <bits/stdc++.h>
using namespace std;

#define int long long

const int INF = 3000000;
const int MOD = 1e9+7;


signed main() {
    ios_base::sync_with_stdio(0);
    cout.tie(0);
    int n, m;
    cin >> n >> m;
    vector<pair<int, int> > a(n+m-2);
    for(int i = 0; i < n-1; i++) {
        cin >> a[i].first;
        a[i].second = 0;
    }
    for(int i = 0; i < m-1; i++) {
        cin >> a[n+i-1].first;
        a[n+i-1].second = 1;
    }

    sort(a.rbegin(), a.rend());

    int egyik = 0, masik = 0;

    int ans = 0;

    for(int i = 0; i < n+m-2; i++) {
        //cout << a[i].first << ' ' << a[i].second << endl;
        if (a[i].second == 0) {
            egyik++;
            ans += a[i].first + (a[i].first * masik);
        }
        if (a[i].second == 1) {
            masik++;
            ans += a[i].first + (a[i].first * egyik);
        }
    }

    cout << ans << endl;

}