#include <bits/stdc++.h>
using namespace std;
#define fastio ios_base::sync_with_stdio(false); cin.tie(NULL);
#define deb(x) cout<<#x<<'='<<x<<'\n';
#define deb2(x,y) cout<<#x<<'='<<x<<", "<<#y<<'='<<y<<'\n';
#define int long long
#define all(x) (x).begin(), (x).end()
#define pii pair<int, int>
#define pb push_back
#define f first
#define s second
#define sz(x) (int)(x).size()
const long double PI = acos(-1);
const int mod = 1e9 + 7, inf = 1e18;
const int D = 2e5 + 10;
// UG - internal editorial
signed main() {
fastio
//freopen("../input1.txt", "r", stdin);
//freopen("../output1.txt", "w", stdout);
int n, m; cin >> n >> m;
int a[n + 5] = {0};
for (int i = 1; i <= n; i++)
cin >> a[i];
int b[n + 5] = {0};
for (int i = 1; i <= n; i++)
b[i] = m * i - a[i];
vector<int> v;
for (int i = 1; i <= n; i++) {
if (b[i] < 0) continue;
auto p = upper_bound(all(v), b[i]) - v.begin();
if (p == sz(v)) v.pb(b[i]);
else v[p] = b[i];
}
cout << n - sz(v) << '\n';
return 0;
}
