#include "bits/stdc++.h"
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace std;
using namespace __gnu_pbds;
#define all(x) x.begin(), x.end()
#define pb push_back
#define sz(x) (int)(x.size())
#define ll long long
#define fi first
#define se second
#define lbd lower_bound
#define ubd upper_bound
template <typename T>
using ordered_set = tree<T, null_type,
less<T>, rb_tree_tag,
tree_order_statistics_node_update>;
const int MOD = 1e9 + 7;
const double eps = 1e-10;
const long long INF = 1e18;
const int N = 2e5 + 10;
void solve() {
int n, m;
cin >> n >> m;
vector<int> v(n + 1);
for (int i = 1; i <= n; i++) {
cin >> v[i];
v[i] = m * i - v[i];
}
vector<int> dp;
for (int i = 1; i <= n; i++) {
if (v[i] < 0) continue;
auto it = ubd(all(dp), v[i]) - dp.begin();
if (it == sz(dp)) dp.pb(v[i]);
else dp[it] = v[i];
}
cout << n - sz(dp);
}
int main() {
ios::sync_with_stdio(false);
cin.tie(0);
int tt = 1;
//cin >> tt;
while (tt--) {
solve();
cout << '\n';
}
return 0;
}
