#include <bits/stdc++.h>
using namespace std;
int lis(const vector<int> &seq) {
vector<int> min_endings;
for (int i:seq) {
int pos=upper_bound(min_endings.begin(),min_endings.end(),i)-min_endings.begin();
if (pos==min_endings.size()) {
min_endings.push_back(i);
} else {
min_endings[pos]=i;
}
}
return min_endings.size();
}
int main() {
int n,m;
cin >> n >> m;
vector<int> poles(n);
for (int p=0; p<n; p++) {
cin >> poles[p];
}
vector<int> poss_unchanged;
for (int i=1; i<=n; i++) {
if (i*m>=poles[i-1]) {
poss_unchanged.push_back(i*m-poles[i-1]);
}
}
cout << n-lis(poss_unchanged);
}
