#include <bits/stdc++.h>
#define ll long long
#define F first
#define S second
#define all(x) x.begin(), x.end()
#define pb push_back
#define FIO ios_base::sync_with_stdio(false); cin.tie(0); cout.tie(0)
using namespace std;
typedef pair <ll, ll> pii;
int n, m;
int r[107], wh[2007], w[2007];
int main () {
FIO;
cin >> n >> m;
deque <int> q;
set <int> s;
for (int i = 1; i <= n; i++) {
cin >> r[i];
s.insert(i);
}
for (int i = 1; i <= m; i++) {
cin >> w[i];
}
int res = 0;
for (int i = 1; i <= 2*m; i++) {
int x; cin >> x;
if (x > 0) {
if (s.empty()) q.pb(x);
else {
int y = *s.begin();
s.erase(y);
res += w[x] * r[y];
wh[x] = y;
}
}
else {
int y = wh[-x];
s.insert(y);
if (!q.empty()) {
x = q.front();
s.erase(y);
res += w[x] * r[y];
wh[x] = y;
q.pop_front();
}
}
}
cout << res;
return 0;
}
