#include<bits/stdc++.h>
#define pb push_back
#define mp make_pair
#define ff first
#define ss second
using namespace std;
int r[2001];
int w[2001];
int s[2002];
int vis[2001];
int res =0;
int n , m;
int main(){
cin >> n;
cin >>m;
memset(vis , 0 , sizeof(vis));
vector<int> wait;
for(int i = 1; i<=n; i++){
cin >> r[i];
}
for(int i = 1; i<=m; i++){
cin >> w[i];
}
for(int i = 1; i<=m * 2; i++){
int tmp;
cin >> tmp;
if(tmp > 0){
bool flag =true;
for(int i = 1; i<=n; i++){
if(vis[i] == 0){
res+=r[i] * w[tmp];
vis[i] = tmp;
flag = false;
break;
}
}
if(flag) wait.pb(tmp);
}
else {
int sul = -1;
for(int i = 1; i<=n; i++){
if(vis[i] == tmp * (-1)){
vis[i] = 0;
sul = i;
break;
}
}
if(wait.size()!=0 ) {
res+=w[wait[0]] * r[sul];
vis[sul] = wait[0];
wait.erase(wait.begin());
}
}
}
cout << res << endl;
return 0;
}
