// #pragma GCC optimize("Ofast,unroll-loops")
// #pragma GCC target("avx,avx2,sse,sse2")
#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace __gnu_pbds;
using namespace std;
#define ll long long
#define ld long double
#define all(x) x.begin(), x.end()
#define rall(x) x.rbegin(), x.rend()
#define pb push_back
#define eb emplace_back
#define F first
#define S second
#define mp make_pair
#define random mt19937 rng(chrono::steady_clock::now().time_since_epoch().count())
template <typename T> using oset = tree <pair <T, T>, null_type, less <pair <T, T>>, rb_tree_tag, tree_order_statistics_node_update>;
template <typename Container>
void Print(Container& container, int starting) {
auto Start = container.begin(), End = container.end();
while (Start != End) cout << *(Start++) << " ";
cout << '\n';
}
template <typename T>
void print(T&& t) {cout << t << '\n';}
template <typename T, typename... Args>
void print(T&& t, Args&&... args) {
cout << t << " ";
print(forward<Args>(args)...);
}
inline void solve() {
int n, m, ans = 0;
cin >> n >> m;
vector <int> s(n), w(m), p(n);
set <int> spots;
for (int i = 0; i < n; ++i) {
cin >> s[i];
spots.insert(i);
}
for (int i = 0; i < m; ++i) cin >> w[i];
queue <int> q;
for (int i = 0; i < 2 * m; ++i) {
int x;
cin >> x;
if (x > 0) {
q.emplace(x);
} else {
x *= -1;
spots.insert(p[x - 1]);
p[x - 1] = 0;
}
while (!q.empty() && !spots.empty()) {
int cur = q.front();
auto place = spots.begin();
spots.erase(place);
p[cur - 1] = *place;
ans += (w[cur - 1] * s[*place]);
q.pop();
}
}
print(ans);
}
int32_t main() {
ios_base::sync_with_stdio(false);
cin.tie(nullptr);
cout.tie(nullptr);
int T = 1;
// cin >> T;
for (int test = 1; test <= T; ++test) {
// cout << "Case #" << test << ": ";
solve();
}
}
