#define _CRT_SECURE_NO_WARNINGS

#include<cstring>

#include<cctype>

#include<cmath>

#include<cstdio>

#include<string>

#include<stack>

#include<ctime>

#include<list>

#include<set>

#include<map>

#include<queue>

#include<vector>

#include<sstream>

#include<iostream>

#include<algorithm>

//#define INF 0x3f3f3f3f

#define eps 1e-6

#define pi acos(-1.0)

#define e exp(1.0)

#define fre(i,t,n)  for(int i =(t);i<=(n);++i)

#define fer(i,n,t)  for(int i =(n);i>=(t);--i)

#define mp make_pair

#define pb push_back

//std::ios::sync_with_stdio(false);

using namespace std;

typedef long long ll;

typedef unsigned long long ull;

void smain();

#define ONLINE_JUDGE

int main() {

    ios::sync_with_stdio(false);

#ifndef ONLINE_JUDGE

    freopen("in.txt", "r", stdin);

    freopen("out.txt", "w", stdout);

    long _begin_time = clock();

#endif

    smain();

#ifndef ONLINE_JUDGE

    long _end_time = clock();

    printf("time = %ld ms.", _end_time - _begin_time);

#endif

return ;

}

const int maxn = 2e5 + +;

const int mod = 1e9 + ;

const ll INF= ()*(200000ll) + ;

ll a[maxn], b[maxn], mx[maxn];

void Run() {

    fre(i, , maxn) mx[i] = -INF;

    int n, k;

    cin >> n >> k;

    fre(i, , n)cin >> a[i];

    fre(i, , n) a[i] += a[i - ];

    fre(i, k, n)b[i] = a[i] - a[i - k];

    fre(i, k, n)mx[i] = max(mx[i - ], b[i]);

    ll ans = -INF;

    fre(i,  * k, n) {

        ans = max(ans, mx[i - k] + b[i]);

    }

    cout << ans ;

}

void smain() {

    int t;

    cin >> t;

    while (t--) {

        Run();

        cout << endl;

    }

}