#include<bits/stdc++.h>
using namespace std;
#define int long long
signed main(){
int n, m; cin >> n >> m;
vector<int> r(n);
for (int i=0; i<n; i++) cin >> r[i];
vector<int> w(m);
for (int i=0; i<m; i++) cin >> w[i];
vector<bool> t(n, false);
vector<int> s(m);
int res = 0;
queue<int> q;
for (int i=0; i<2*m; i++){
int x;
cin >> x;
if (x < 0){
x++; x = -x;
t[s[x]] = false;
if (!q.empty()){
t[s[x]] = true;
s[q.front()] = s[x];
//cout << r[s[x]] << " " << w[q.front()] << ": ";
res += r[s[x]] * w[q.front()];
q.pop();
//cout << res << "\n";
}
continue;
}
x--;
int j = 0;
while (t[j] && j<n) j++;
if (j == n){
q.push(x);
continue;
}
t[j] = true;
s[x] = j;
res += r[j] * w[x];
//cout << res << "\n";
}
cout << res << "\n";
}
