#include<bits/stdc++.h>
using namespace std;
#define fast ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0)
#define ll long long
#define vll vector<ll>
#define vvll vector<vll>
#define FOR(i,a,b) for(ll i = a;i<b;i++)
#define pll pair<ll,ll>
#define pii pair<int,int>
#define pb push_back
#define Ye cout<<"YES\n"
#define No cout<<"NO\n";
#define pq priority_queue<ll>
void in(ll n, ll a[]){
    for(int i = 1;i<=n;i++){
        cin >> a[i];
    }
}
void out(int n, int a[]){
    for(int i = 0;i<n;i++){
        cout << a[i] << " ";
    }
}
const int maxn = 2e5+5;
ll n,k;
ll d[maxn];
ll u = 1;
ll v = 0;
ll f(ll u, ll x){
    return max(n - (x-u+1)*(k+1)+1,1LL);
}
void solve(){
    cin >> n >> k;
    ll x = n/(k+1);
    u = 1;
    v = f(u,x);
    in(n,d);
    pq p;
    ll ans = 0;
    FOR(i,0,n){
        p.push(d[i]);
        if(i == v){
            ans+=p.top();
            p.pop();
            if(u < x){
                u++;
                v = f(u,x);
            }
        }
    }
    cout << ans << "\n";
}

signed main(){
    fast;
    int t = 1; cin >> t;
    while(t--)solve();
}