#include <iostream>
#include <cmath>
#include <algorithm>
using namespace std;
void bevekt(int a[], int n) {
    for (int i = 0; i < n - 1; i++) {
        cin >> a[i];
    }
}
void rendezvekt(int a[], int n) {
    for (int i = 0; i < n - 2; i++) {
        for (int j = i+1; j < n-1; j++) {
            if (a[i] < a[j]) {
                swap(a[i], a[j]);
            }
        }
    }
}
void solve(int a[], int b[], int n, int m) {
    int i = 0, j = 0;
    int s = 0;
    while (i < n - 1 && j < m - 1) {
        if (a[i] * (j+1) > b[j] * (i+1)) {
            s += a[i] * (j+1);
            i++;
        }
        else {
            s += b[j] * (i+1);
            j++;
        }
    }
    while (i < n - 1) {
        s += a[i] * (j+1);
        i++;
    }
    while (j < m - 1) {
        s += b[j] * (i+1);
        j++; 
    }
    cout << s;
}
int a[100002];
int b[100002];
int main()
{
    int n, m;
    cin >> n >> m;
    bevekt(a, n);
    bevekt(b, m);
    sort(a,a+n-1,greater<int>());
    sort(b,b+m-1,greater<int>());
    solve(a, b, n, m);
}