#include <algorithm>
#include <iostream>
#include <numeric>
#include <cassert>
#include <vector>
#include <queue>
#include <set>
typedef long long llong;
const int MAXN = 2000 + 10;
const int INF = 1e9;
int n, m, p;
int r[MAXN];
int w[MAXN];
int at[MAXN];
int takenBy[MAXN];
std::queue <int> q;
std::set <int> avaliable;
void solve()
{
for (int i = 1 ; i <= n ; ++i)
{
avaliable.insert(i);
}
int ans = 0;
for (int i = 1 ; i <= 2 * m ; ++i)
{
int idx;
std::cin >> idx;
if (idx > 0)
{
q.push(idx);
} else
{
idx = -idx;
takenBy[at[idx]] = 0;
avaliable.insert(at[idx]);
}
while (avaliable.size() && q.size())
{
int front = q.front();
q.pop();
ans += r[*avaliable.begin()] * w[front];
takenBy[*avaliable.begin()] = front;
at[front] = *avaliable.begin();
avaliable.erase(avaliable.begin());
}
}
std::cout << ans << '\n';
}
void input()
{
std::cin >> n >> m;
for (int i = 1 ; i <= n ; ++i)
{
std::cin >> r[i];
}
for (int i = 1 ; i <= m ; ++i)
{
std::cin >> w[i];
}
}
void fastIOI()
{
std::ios_base :: sync_with_stdio(0);
std::cout.tie(nullptr);
std::cin.tie(nullptr);
}
int main()
{
fastIOI();
input();
solve();
return 0;
}
