#include <bits/stdc++.h>   using namespace std;   int main() {     int t, n, k, tmp;     vector<long long> ans;     vector<int> vec;     cin >> t;     while (t--) {       cin >> n >> k;       for (int i = 0; i < n * k; i++) {         cin >> tmp;         vec.push_back(tmp);       }       int med;       if (n % 2 == 0)         med = n / 2;       else         med = n / 2 + 1;       long long medSum = 0;       int pos = vec.size() - (n - med) - 1;       for (int i = 0; i < k; i++) {         medSum += (long long)vec[pos];         pos -= (n - med + 1);       }       ans.push_back(medSum);       vec.clear();     }     for (int i = 0; i < ans.size(); i++) cout << ans[i] << endl;   }   