#include <iostream>
#include <queue>
using namespace std;
int espacio[102];
int carros[2002];
int cubeta[102];
queue<int> cola;
int main(){
ios_base::sync_with_stdio(0);
int n, m, aux;
int tot = 0;
cin >> n >> m;
for (int i = 1; i <= n; i++){
cin >> espacio[i];
}
for (int i = 1; i <= m; i++){
cin >> carros[i];
}
int lugar = 1;
for (int i = 1; i <= m * 2; i++){
cin >> aux;
if (aux > 0){
lugar = 0;
for (int j = 1; j <= n; j++){
if (cubeta[j] == 0){
cubeta[j] = aux;
lugar = j;
break;
}
}
if (lugar != 0){
tot += espacio[lugar] * carros[aux];
}else{
cola.push(aux);
}
}else{
for (int j = 1; j <= n; j++){
if (cubeta[j] == abs(aux)){
cubeta[j] = 0;
lugar = j;
}
}
if (cola.size() >= 1){
int f = cola.front();
cola.pop();
tot += espacio[lugar] * carros[f];
cubeta[lugar] = f;
}
}
}
cout << tot;
return 0;
}
