#include <iostream>
#include <vector>
#include <queue>
using namespace std;
int findSpace(vector<int>& arr) {
for (int i = 0; i < arr.size(); i++) {
if (!arr[i]) {
return i;
}
} return -1;
}
int findSpace(vector<int>& arr, int x) {
for (int i = 0; i < arr.size(); i++) {
if (arr[i] == x) {
return i;
}
} return -1;
}
int main() {
int n, m;
cin >> n >> m;
vector<int> prices(n);
for (int i = 0; i < n; i++) {
cin >> prices[i];
}
vector<int> weights(m);
for (int i = 0; i < m; i++) {
cin >> weights[i];
}
long long sum = 0;
vector<int> spaces(n, 0);
queue<int> cars;
for (int i = 0; i < 2 * m; i++) {
int x;
cin >> x;
if (x > 0) {
int space = findSpace(spaces);
if (space != -1) {
spaces[space] = x;
sum += prices[space] * weights[x - 1];
} else {
cars.push(x);
}
} else {
if (cars.size()) {
int space = findSpace(spaces, -x);
spaces[space] = cars.front();
sum += prices[space] * weights[cars.front() - 1];
cars.pop();
} else {
int space = findSpace(spaces, -x);
spaces[space] = 0;
}
}
}
cout << sum;
}
