#include <iostream>
#include <vector>
#include <queue>
#include <algorithm>
using namespace std;
using ll = long long;
#define MIN(a, b) (((a) < (b)) ? (a) : (b))
#define MAX(a, b) (((a) < (b)) ? (b) : (a))
int const nmax = 2000;
int coef[1 + nmax], weight[1 + nmax];
int place[1 + nmax];
int main()
{
int n, m;
cin >> n >> m;
for(int i = 1;i <= n; i++)
cin >> coef[i];
for(int i = 1; i <= m; i++)
cin >> weight[i];
priority_queue<int, vector<int>, greater<int>> pq;
for(int i = 1; i <= n; i++)
pq.push(i);
ll result = 0;
queue<int> q;
for(int i = 1;i <= 2 * m; i++){
int op;
cin >> op;
if(op < 0){
op = -op;
pq.push(place[op]);
} else
q.push(op);
while(0 < q.size() && 0 < pq.size()){
int car = q.front();
q.pop();
int target = pq.top();
pq.pop();
place[car] = target;
result += weight[car] * coef[target];
}
}
cout << result;
return 0;
}
