#include <bits/stdc++.h>
// #include <ext/pb_ds/assoc_container.hpp>
using namespace std;
// using namespace __gnu_pbds;
#define SPEED \
ios_base::sync_with_stdio(0); \
cin.tie(NULL); \
cout.tie(NULL);
#define pb push_back
#define ins insert
#define fi first
#define se second
#define endl "\n"
#define ALL(x) x.begin(), x.end()
#define sz(x) x.size()
#define intt long long
const intt mod = 1e9 + 7;
const intt base = 31;
const intt inf = 1e9;
const intt mxN = 2e5 + 5;
const intt L = 21;
void solve() {
intt N, M;
cin >> N >> M;
vector<intt> R(N), W(M), P(M);
for(intt i = 0; i < N; i++) {
cin >> R[i];
}
for(intt i = 0; i < M; i++) {
cin >> W[i];
}
set<intt> st;
queue<intt> q;
for(intt i = 1; i <= N; i++) st.insert(i);
intt profit = 0;
for(intt i = 1; i <= 2 * M; i++) {
intt car;
cin >> car;
if(car > 0) {
q.push(car);
} else {
car = -car;
st.insert(P[car]);
}
while(not st.empty() && not q.empty()) {
P[q.front()] = *st.begin();
profit += W[q.front() - 1] * R[*st.begin() - 1];
q.pop();
st.erase(st.begin());
}
}
cout << profit << endl;
}
signed main() {
SPEED;
intt tst = 1;
// cin >> tst;
while (tst--) {
solve();
}
}
