#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
const int MAX = 2e6 + 15;
const int INF = 0x3f3f3f3f;
ll n, m, rev, r[MAX], w[MAX], spot[MAX];
set<int> s;
queue<int> q;
int main(){
ios_base::sync_with_stdio(false);
cin.tie(NULL);
cin >> n >> m;
for(int i = 1; i <= n; i++){
cin >> r[i];
s.insert(i);
}
for(int i = 1; i <= m; i++)
cin >> w[i];
for(int i = 1; i <= 2 * m; i++){
int car; cin >> car;
if(car < 0) car = -car;
if(spot[car] != 0){
s.insert(spot[car]);
if(q.size()){
int nx = q.front(); q.pop();
spot[nx] = spot[car];
rev += r[spot[nx]] * w[nx];
}else{
s.insert(spot[car]);
}
}else{
if(s.size()){
int curSpot = *s.begin();
s.erase(s.begin());
spot[car] = curSpot;
rev += r[spot[car]] * w[car];
}else{
q.push(car);
}
}
}
cout << rev << '\n';
}
