/**
____ ____ ____ ____ ____
||a |||t |||o |||d |||o ||
||__|||__|||__|||__|||__||
|/__\|/__\|/__\|/__\|/__\|
**/
#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
int main () {
ios_base::sync_with_stdio(false);
cin.tie(0);
cout.tie(0);
int N, M;
cin >> N >> M;
int R[N];
for (int i = 0; i < N; i++) {
cin >> R[i];
}
int W[M];
for (int j = 0; j < M; j++) {
cin >> W[j];
}
int pos[M];
set <int> sfree;
queue <int> waiting;
for (int i = 0; i < N; i++) {
sfree.insert(i);
}
int answer = 0;
for (int k = 0; k < M * 2; k++) {
int j;
cin >> j;
if (j < 0) {
j = -j; j--;
sfree.insert(pos[j]);
} else {
j--;
waiting.push(j);
}
if (sfree.empty() == false && waiting.empty() == false) {
int j = waiting.front();
waiting.pop();
pos[j] = *sfree.begin();
sfree.erase(sfree.begin());
answer += R[pos[j]] * W[j];
}
}
cout << answer << "\n";
return 0;
}
