/*
Problem link: https://oj.uz/problem/view/LMIO19_triusis
Tags:
*/
#include<bits/stdc++.h>
using namespace std;
//#define MULTI
#define ll long long
#define all(x) (x).begin(), (x).end()
void solve() {
ll n, k;
cin >> n >> k;
vector<ll> a(n+1), dp;
for (ll i = 1; i <= n; i++)
{
cin >> a[i];
a[i] = k*i-a[i];
}
for (ll i = 1; i <= n; i++)
{
if(a[i] < 0) continue;
auto t = upper_bound(all(dp), a[i]);
if(t == dp.end()) {
dp.push_back(a[i]);
}
else {
dp[t-dp.begin()] = a[i];
}
}
cout << n-dp.size() << endl;
}
int main(int argc, char **argv)
{
ios::sync_with_stdio(false);
cin.tie(0);
#ifdef MULTI
int t;
cin >> t;
while (t--)
{
solve();
}
#else
solve();
#endif
return 0;
}
