#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
const ll mod = 1e9 + 7;
#pragma GCC optimize("Ofast")
#define vi vector<int>
#define vll vector<ll>
#define pii pair<int, int>
#define mp make_pair
#define pb push_back
#define lb lower_bound
#define ub upper_bound
#define fi first
#define sc second
#define endl '\n'
#define gl ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
int main()
{
int n, m;
cin >> n >> m;
int r[n + 1], w[m + 1], p[m + 1];
priority_queue<int, vector<int>, greater<int> > ada;
queue<int> q;
for(int i = 1; i <= n; i++) cin >> r[i];
for(int i = 1; i <= m; i++) cin >> w[i];
ll ans = 0;
for(int i = 1; i <= n; i++) ada.push(i);
for(int i = 1; i <= 2 * m; i++){
int x;
cin >> x;
if(x > 0){
if(ada.empty()) q.push(x);
else{
int pos = ada.top();
ada.pop();
ans += r[pos] * w[x];
p[x] = pos;
}
}
else{
x *= -1;
ada.push(p[x]);
if(!q.empty()){
int pake = q.front();
int pos = ada.top();
ada.pop();
q.pop();
ans += r[pos] * w[pake] * 1LL;
p[pake] = pos;
}
}
}
cout << ans << endl;
}
