#include <bits/stdc++.h>
#define DIM 2010
using namespace std;
int aib[DIM],r[DIM],g[DIM],v[DIM];
int n,m,i,x;
deque <int> d;
void update (int p, int val){
for (;p<=n;p+=(p&-p))
aib[p] += val;
}
int query (int p){
if (p <= 0)
return 0;
int sol = 0;
for (;p;p-=(p&-p))
sol += aib[p];
return sol;
}
int main (){
//ifstream cin ("date.in");
//ofstream cout ("date.out");
cin>>n>>m;
for (i=1;i<=n;i++)
cin>>r[i];
for (i=1;i<=m;i++)
cin>>g[i];
long long sol = 0;
for (i=1;i<=2*m;i++){
cin>>x;
if (x > 0) /// ajunge o noua masina
d.push_back(x);
else {
x = -x;
update (v[x],-1);
v[x] = 0;
}
if (d.empty())
continue;
if (query(n) == n) /// nu am loc
continue;
int st = 1, dr = n, poz = 0;
while (st <= dr){
int mid = (st+dr)>>1;
if (query(mid) < mid){
poz = mid;
dr = mid-1;
} else st = mid+1;
}
int idx = d.front();
d.pop_front();
sol += 1LL * r[poz] * g[idx];
v[idx] = poz;
update (poz,1);
}
cout<<sol;
return 0;
}
