#include <algorithm>
#include <iostream>
#include <string>
#include <vector>

using namespace std;

class MinQueue {
private:
    vector<int> data;
    size_t dataBegin;
    vector<int> minData;
    size_t minDataBegin;

public:
    void push(int val) {
        data.push_back(val);
        while (minData.size() > minDataBegin && minData.back() > val) {
            minData.pop_back();
        }
        minData.push_back(val);
    }

    int min() {
        return minData[minDataBegin];
    }

    void pop() {
        if (minData[minDataBegin] == data[dataBegin++]) {
            ++minDataBegin;
        }
    }

    void clear() {
        dataBegin = minDataBegin = 0;
        data.clear();
        minData.clear();
    }
};

int main() {
    MinQueue q;
    int n, k;
    cin >> n >> k;
    vector<int> a(n);
    for (auto &x : a) {
        cin >> x;
    }
    int len;
    int ans = 0;
    while (k--) {
        q.clear();
        cin >> len;
        for (int i = 0; i < len; ++i) {
            q.push(a[i]);
        }
        int curAns = q.min();
        for (int i = len; i < n; ++i) {
            q.pop();
            q.push(a[i]);
            curAns = max(curAns, q.min());
        }
        ans += curAns;
    }
    cout << ans << '\n';
}