3

#include <bits/stdc++.h> #define int long long

using namespace std;

signed main() { ios::sync_with_stdio(false); cin.tie(0);

int t; cin >> t;
while (t --)
{
    int n, m; cin >> n >> m;
    int sum = 0;
    vector<int> p;
    for (int i = 0; i < n; i ++)
    {
        int x; cin >> x;
        sum += x;
        if (x > 0) p.push_back(x * (n - i));
    }
    sort(p.begin(), p.end());
    for (int i = p.size() - 1; ~i && m; i --) sum -= p[i], m --;
    cout << sum << "\n";
}
return 0;

}