#include <algorithm>
#include <iostream>
#include <vector>
using namespace std;
int max_non_dec_subseq(const vector<int> &seq) {
vector<int> dp;
for (auto x : seq) {
int pos = upper_bound(dp.begin(), dp.end(), x) - dp.begin();
if (pos == dp.size()) {
dp.push_back(x);
}
else {
dp[pos] = x;
}
}
return dp.size();
}
int main() {
int n, m; cin >> n >> m;
int a[n+1];
a[0] = 0;
for (int i=1; i<=n; i++) {
cin >> a[i];
a[i] -= i*m;
}
vector<int> poss_unchanged;
for (int i=0; i<=n; i++) {
if (a[i] <= 0) { poss_unchanged.push_back(-a[i]); }
}
cout << (n+1) - max_non_dec_subseq(poss_unchanged) << '\n';
}
