#include <bits/stdc++.h>
using namespace std;
int main() {
int n, m, res = 0;
cin >> n >> m;
vector<int> rates(n);
for (int i = 0; i < n; ++i) cin >> rates[i];
vector<int> weights(m);
for (int i = 0; i < m; ++i) cin >> weights[i];
priority_queue<int, vector<int>, greater<int>> free_spots;
for (int i = 0; i < n; ++i) free_spots.push(i);
queue<int> waiting;
unordered_map<int, int> parked;
for (int i = 0; i < 2 * m; ++i) {
int x;
cin >> x;
if (x > 0) {
x--; // 0-based
if (!free_spots.empty()) {
int spot = free_spots.top(); free_spots.pop();
res += weights[x] * rates[spot];
parked[x] = spot;
} else {
waiting.push(x);
}
} else {
x = -x - 1;
if (parked.find(x) == parked.end()) {
continue; // skip auto koji nije parkiran
}
int spot = parked[x];
parked.erase(x);
if (!waiting.empty()) {
int next = waiting.front(); waiting.pop();
res += weights[next] * rates[spot];
parked[next] = spot;
} else {
free_spots.push(spot);
}
}
}
cout << res << '\n';
}
