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

int main() {
	long long n, m;
	cin >> n >> m;
	
    vector<pair<long long, long long>> sor;
    
    for (long long i = 0; n-1 > i; i++) {
        long long temp;
        cin >> temp;
        
        sor.push_back({temp, 0});
    }
    
    for (long long j = 0; m-1 > j; j++) {
        long long temp;
        cin >> temp;
        
        sor.push_back({temp, 1});
    }
	
	long long xSzor = 1;
	long long ySzor = 1;
	
	sort(sor.rbegin(), sor.rend());
	
	long long osszeg = 0;
	
	for (long long i = 0; sor.size() > i; i++) {
	    long long current = sor[i].first;
	    long long melyik = sor[i].second;
	    
	    if (melyik == 0) {
	        osszeg += current * xSzor;
	        ySzor++;
	    } else {
	        osszeg += current * ySzor;
	        xSzor++;
	    }
	}
	
	cout << osszeg << endl;
	
    return 0;
}