#include <bits/stdc++.h>
#define ll long long
#define pii pair<int, int>
#define endl '\n'
#define int ll
using namespace std;
void dbg(vector<int> &arr)
{
cout << "[";
for (int &i : arr)
cout << ' ' << i;
cout << " ]" << endl;
}
signed main()
{
ios_base::sync_with_stdio(0);
cin.tie(0);
int N, M;
cin >> N >> M;
vector<int> arr;
for (int i = 1; i <= N; i++)
{
int x;
cin >> x;
arr.push_back(x - (M * i));
if (arr.back() > 0)
arr.pop_back();
}
int sz = arr.size();
vector<int> lis;
for (int i = 0; i < sz; i++)
{
if (lis.empty() || lis.back() >= arr[i])
{
lis.push_back(arr[i]);
// dbg(lis);
continue;
}
int l = 0, r = lis.size() - 1;
int lb = 0;
while (l <= r)
{
int m = l + (r - l) / 2;
if (lis[m] < arr[i])
{
lb = m;
r = m - 1;
}
else
l = m + 1;
}
lis[lb] = arr[i];
// dbg(lis);
}
cout << N - lis.size() << endl;
}
