#include <iostream>                                                                                                                                              
#include <vector>                                                                                                                                                
#include <algorithm>                                                                                                                                             
                                                                                                                                                                 
using namespace std;                                                                                                                                             
                                                                                                                                                                 
int main() {                                                                                                                                                     
    int m, n;                                                                                                                                                    
    cin >> m >> n;                                                                                                                                               
                                                                                                                                                                 
    vector<int> horizontal_cuts(m - 1);                                                                                                                          
    for (int i = 0; i < m - 1; i++) {                                                                                                                            
        cin >> horizontal_cuts[i];                                                                                                                               
    }                                                                                                                                                            
                                                                                                                                                                 
    vector<int> vertical_cuts(n - 1);                                                                                                                            
    for (int i = 0; i < n - 1; i++) {                                                                                                                            
        cin >> vertical_cuts[i];                                                                                                                                 
    }                                                                                                                                                            
                                        
    int total_cost = 0;              
    for (int i = 0; i < m - 1; i++) {                                           
        for (int j = 0; j < n - 1; j++) {                                                                                                                        
            int cost = min(horizontal_cuts[i], vertical_cuts[j]);
            total_cost += cost;                                                 
        }                                                                       
    }                                   
                                        
    cout << total_cost << endl;         
                                        
    return 0;                  
}