#include<bits/stdc++.h>
using namespace std;
#define getbit(n, i) (((n) & (1LL << (i))) != 0) 
#define setbit0(n, i) ((n) & (~(1LL << (i)))) 
#define setbit1(n, i) ((n) | (1LL << (i))) 

#define ll long long
template<typename s, typename t> void smax(s &a, const t &b) {if (a<b) a=b;}
template<typename s, typename t> void smin(s &a, const t &b) {if (a>b) a=b;}
char gap = 32;

#define rng_init mt19937 rng(chrono::steady_clock::now().time_since_epoch().count())
#define rng_seed(x) mt19937 rng(x)
#define fill(x, y) memset(x, y, sizeof(x))
#define srt(v) sort(v.begin(), v.end())
#define rsrt(v) sort(v.rbegin(),v.rend())
#define pb push_back
#define lll __int128_t
ll hashPrime = 1610612741;

void solve(){
    int n, k;
    cin >> n >> k;
    vector<int> v(n);
    for (int i = 0; i < n; ++i) {
        cin >> v[i];
    }

    vector<unordered_map<int, int> > freq(k);
    for (int i = 0; i < n; i++) {
        freq[i % k][v[i]]++;
    }
        
    int cnt = 0;
    for (int i = 0; i < k; i++) {
        int mx = 0;
        int total = 0;
        for (auto& [val, count] : freq[i]) {
            mx = max(mx, count);
            total += count;
        }
        cnt += total - mx;
    }
    cout << cnt << endl;
}

signed main(){
    ios_base::sync_with_stdio(false);
    cin.tie(0);
    cout.tie(0);
    int t; cin >> t;
    while(t--){
        solve();
    }
}