#include <iostream>
#include <math.h>
#include <vector>
#include <string>
#include <algorithm>
#include <queue>
#include <stack>
#include <map>
#include <cstring>
#include <iomanip>
#include <set>
#include <bitset>
using namespace std;
using ll = long long;
using pii = pair<int,int>;
using piii = tuple<int,int,int>;
#define endl '\n'
#define f first
#define s second
int main(){
int n,m;cin >> n >> m;
vector<int> park(n);
for(auto &i:park) cin >> i;
vector<int> weight(m);
for(auto &i:weight) cin >> i;
queue<int> q;
vector<int> full(n,0);
int sum = 0;
for(int i{};i < m*2;i++){
int g;cin >> g;
if(g > 0){
q.push(g);
}
else{
for(int i = 0;i < n;i++){
if(full[i] == -g){
full[i] = 0;
}
}
}
for(int i = 0;i < n;i++){
if(q.empty()) break;
if(full[i] == 0){
sum += park[i]*weight[q.front()-1];
full[i] = q.front();q.pop();
}
}
}
cout << sum;
}
