//#ifndef khos
//#pragma GCC optimize ("Ofast")
//#pragma GCC optimize ("unroll-loops")
//#endif
#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
#ifdef khos
#include "t_debug.cpp"
#else
#define debug(...) 42
#endif
using namespace std;
using namespace __gnu_pbds;
template<typename T> using ordered_set = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
template<typename T> using indexed_multiset = tree<pair<int,int>, null_type, less<pair<int,int>>, rb_tree_tag, tree_order_statistics_node_update>;
#define int int64_t
#define vi vector
#define ss second
#define ff first
#define TESTCASES
#define all(x) (x).begin(), (x).end()
const int mod = 1e9+7;
const int MAXN=2000000+5;
const int inf=1e18;
int lis(vi<int> a){
debug(a);
vi<int> vec;
for(int i=0; i<a.size(); i++){
int hi=upper_bound(all(vec), a[i]) - vec.begin();
if(hi==vec.size()){
vec.push_back(a[i]);
}
else {
vec[hi]=a[i];
}
}
return vec.size();
}
void solution() {
int n,m;
cin >> n >> m;
vi<int> a(n+1);
for(int i=1; i<=n; i++)cin >> a[i];
vi<int> vec;
for(int i=1; i<=n; i++){
if(i*m>=a[i]){
vec.push_back(i*m-a[i]);
}
}
cout << n-lis(vec);
}
int32_t main(){
clock_t tStart = clock();
// freopen("cowjog.in", "r", stdin);
// freopen("cowjog.out", "w", stdout);
#ifdef khos
freopen("input.txt", "r", stdin);
freopen("output.txt", "w", stdout);
#endif
std::ios::sync_with_stdio(0); cin.tie(0); cout.tie(0);
int q = 1;
#ifdef TESTCASES
// cin >> q;
#endif
while(q--) {
solution();
cout << '\n';
}
cerr<<fixed<<setprecision(3)<<"\nTime Taken: "<<(double)(clock()- tStart)/CLOCKS_PER_SEC<<endl;
}
