#include<bits/stdc++.h>
using namespace std;
#define fast ios_base::sync_with_stdio(false); cin.tie(NULL); cout.tie(NULL);
#define ll long long int
const ll N = 100+5 , INF = 1e18 , MOD = 1e9+7;
void solve(){
ll n,m;
cin >> n >> m;
vector<ll> a(n+5);
for(ll i = 1; i <= n; i++) cin >> a[i];
vector<ll> w(m+5);
for(ll i = 1; i <= m; i++) cin >> w[i];
set<ll> space;
for(ll i = 1; i <= n; i++) space.insert(i);
vector<ll> occupied(m+5);
queue<ll> q;
ll ans = 0;
for(ll i = 1; i <= 2*m; i++){
ll x;
cin >> x;
if(x > 0){
if(!space.size()) q.push(x);
else{
auto it = space.begin();
ll y = (*(it));
ans += a[y]*w[x];
space.erase(space.begin());
occupied[x] = y;
}
}
else{
x *= -1;
space.insert(occupied[x]);
if(q.size()){
ll y = q.front();
q.pop();
auto it = space.begin();
ll z = (*(it));
ans += a[z]*w[y];
space.erase(space.begin());
occupied[y] = z;
}
}
}
cout << ans;
}
int main(){
fast;
ll tc = 1;
// cin >> tc;
while(tc--) solve();
return 0;
}
