#include <bits/stdc++.h>
#define TIME (1.0 * clock() / CLOCKS_PER_SEC)
#define F first
#define S second
#define pb push_back
#define pf push_front
#define pob pop_back
#define pof pop_front
#define sz(s) s.size()
using namespace std;
typedef long long ll;
typedef pair<ll,ll> pll;
const ll MOD = 1e9+7;
const ll INF = 4e18;
const ll MAX = 200007;
ll n, m, a[MAX], dp[MAX];
vector <ll> lis;
void solve() {
cin >> n >> m;
for(ll i=1; i<=n; ++i) cin >> a[i];
for(ll i=1; i<=n; ++i) a[i] = - (a[i] - m*i);
for(ll i=1; i<=n; ++i) {
if(a[i] < 0) continue;
auto p = upper_bound(lis.begin(), lis.end(), a[i]);
if(p == lis.end()) lis.pb(a[i]);
else *p = a[i];
}
cout << n - sz(lis);
}
signed main() {
ios_base::sync_with_stdio(0);
cin.tie(0); cout.tie(0);
// freopen("TASK.INP","r",stdin);
// freopen("TASK.OUT","w",stdout);
solve();
cerr << "\n" << "Time elapsed: " << TIME << "s\n";
return 0;
}
