#include <bits/stdc++.h>
using namespace std;
int main(){
cin.tie(0) -> ios_base::sync_with_stdio(0);
int n, m;
cin >> n >> m;
vector<int> r(n + 1), w(m + 1);
for(int i=1;i<=n;i++) cin >> r[i];
for(int i=1;i<=m;i++) cin >> w[i];
priority_queue<int, vector<int>, greater<int>> pq;
for(int i=1;i<=n;i++) pq.push(i);
queue<int> q;
vector<int> loc(m + 1); // where car i is parked
long long ans = 0;
for(int i=1;i<=2*m;i++)
{
int x;
cin >> x;
if(x < 0)
{
pq.push(loc[-x]);
}
else
{
q.push(x);
}
while(!pq.empty() && !q.empty()){
int cur = q.front(); q.pop();
int p = pq.top(); pq.pop();
loc[cur] = p;
ans += (long long)r[p] * w[cur];
}
}
cout << ans << '\n';
}
