#include <iostream>
#include <vector>
#include <queue>
int main()
{
int N,M;
std::cin >> N >> M;
std::vector<int> rate(N);
for(auto& i : rate) std::cin >> i;
std::vector<int> weight(M);
for(auto& i : weight) std::cin >> i;
weight.emplace(weight.begin()); // 1-indexing
std::priority_queue<int,std::vector<int>,std::greater<int>> spaces;
for(int i = 0; i < N; i++) spaces.push(i);
std::queue<int> queue;
std::vector<int> space(N+1);
long long c = 0;
for(int i = 0; i < 2*M; i++)
{
int op;
std::cin >> op;
if(op > 0)
queue.push(op);
else
spaces.push(space[-op]);
while(queue.size() && spaces.size())
{
auto car = queue.front(); queue.pop();
auto sp = spaces.top(); spaces.pop();
space[car] = sp;
c += weight[car] * rate[sp];
}
}
std::cout << c << "\n";
}
