#include <bits/stdc++.h>
using namespace std;
#define int long long int
void solve() {
int n, m, ans = 0;
cin >> n >> m;
vector<int> r(n+1), w(m+1), space(m+1, -1);
priority_queue<int> available;
queue<int> cars;
for (int i = 1; i <= n; i++) {
cin >> r[i];
available.push(-i);
}
for (int i = 1; i <= m; i++) {
cin >> w[i];
}
for (int i = 0; i < 2*m; i++) {
int x;
cin >> x;
if (x < 0) {
x = abs(x);
ans += w[x]*r[space[x]];
if (!cars.empty()) {
space[cars.front()] = space[x];
cars.pop();
} else {
available.push(-space[x]);
}
} else if (available.empty()) {
cars.push(x);
} else {
space[x] = -available.top();
available.pop();
}
}
cout << ans << endl;
}
int32_t main() {
ios::sync_with_stdio(0);
cin.tie(0);
int t;
t = 1;
while(t--) {
solve();
}
}
