// author: miraiya
#include <bits/stdc++.h>
using namespace std;
#define int long long
#define FOR(i, l, r) for(int i = (l); i <= (r); i++)
#define FOD(i, r, l) for(int i = (r); i >= (l); i--)
#define fi first
#define se second
const int maxn = 1e6 + 10;
const int mod = 1e9 + 7;
signed main()
{
ios_base::sync_with_stdio(0);
cin.tie(0);cout.tie(0);
int n, m;
vector<int> a;
cin >> n >> m;
FOR(i, 1, n)
{
int x;
cin >> x;
if(i * m - x >= 0)
a.push_back(i * m - x);
}
vector<int> b;
for(auto x : a)
{
int p = upper_bound(b.begin(), b.end(), x) - b.begin();
if(p == b.size())
b.push_back(x);
else
b[p] = x;
}
cout << n - b.size();
}
