#include <bits/stdc++.h>
#define intt long long
#define pb push_back
#define pii pair<int,int>
#define pll pair<intt,intt>
#define F first
#define S second
#define endl '\n'
#define sync \
ios_base::sync_with_stdio(0); \
cin.tie(0); \
cout.tie(0)
using namespace std;
int rates[105],cars[2005],owner[2005];
set<pii>st;
int main() {
sync;
int n,m,res;
cin >> n >> m;
for(int i=1;i<=n;i++){
cin >> rates[i];
}
for(int i=1;i<=m;i++){
cin >> cars[i];
}
res = 0;
queue<int>q;
set<int>free_space;
for(int i=1;i<=n;i++){
free_space.insert(i);
}
m *= 2;
int x;
// queue<int>q;
while(m--){
cin >> x;
if(x > 0){
if(free_space.empty()){
q.push(x);
continue;
}
auto it = free_space.begin();
int place = *it;
owner[x] = place;
free_space.erase(it);
res += rates[place] * cars[x];
}
else{
x = -x;
int oww = owner[x];
//owner[x] = 0;
if(q.empty()){
free_space.insert(oww);
}
else{
int first = q.front();
q.pop();
owner[first] = oww;
res += cars[first] * rates[oww];
}
}
}
cout << res;
return 0;
}
