#include <bits/stdc++.h>
using namespace std;
using ll = long long;
int main() {
ios::sync_with_stdio(false);
cin.tie(nullptr);
// #ifndef ONLINE_JUDGE
// ifstream cin("input.txt");
// #endif // ONLINE_JUDGE
int N, M;
cin >> N >> M;
vector<int> a(N);
for (int i = 0; i < N; ++i) {
cin >> a[i];
}
// aj <= ai + j * M - i * M
// - aj + j * M >= - ai + i * M
vector<int> b;
for (int i = 0; i < N; ++i) {
if ((i + 1) * M >= a[i]) {
b.push_back(-a[i] + i * M);
}
}
vector<int> dp;
for (auto& i : b) {
int id = upper_bound(begin(dp), end(dp), i) - begin(dp);
if (id == dp.size()) dp.push_back(i);
else dp[id] = i;
}
cout << N - dp.size() << endl;
}
