//{ Driver Code Starts
#include<bits/stdc++.h>
using namespace std;

// } Driver Code Ends
class Solution{
public:
   long long maximumSumSubarray(int K, vector<int> &v , int N){

        long arr[N+1] = {};



        for(int i=1; i<=N; i++){

            arr[i] = arr[i-1] + v[i-1];

        }



        long count = 0;



        for(int i=1, j=K; j<=N; i++, j++){

            long x = arr[j] - arr[i-1];

            if(x>count){

                count = x;

            }

        }

        return count;
    }
};

//{ Driver Code Starts.
int main()
{
    int t;
    cin>>t;
    while(t--)
    {
        int N,K;
        cin >> N >> K;;
        vector<int>Arr;
        for(int i=0;i<N;++i){
            int x;
            cin>>x;
            Arr.push_back(x);
        }
        Solution ob;
        cout << ob.maximumSumSubarray(K,Arr,N) << endl;
    }
    return 0;
}
// } Driver Code Ends