#include <bits/stdc++.h>
using namespace std;
#define int long long
typedef pair<int,int> pi;
#define f first
#define s second
#define FAST ios_base::sync_with_stdio(0); cin.tie(0);
#define all(x) x.begin(),x.end()
typedef pair<int, pi> pii;
const int maxn = 110;
const int INF = LLONG_MAX/2;
const int mod = 1e9+7;
int n, m;
int32_t main() {
FAST
cin >> n >> m;
vector <int> v;
v.push_back(0);
for (int i =1;i<=n;i++) {
int h; cin >> h;
v.push_back(m * i - h);
}
vector <int> lis;
lis.push_back(0);
for (int i =1;i<=n;i++) {
int x = v[i];
if (x < 0) continue;
if (lis.empty() or lis.back() <= x) lis.push_back(x);
else {
int pos = lower_bound(all(lis), x) - lis.begin();
lis[pos] = x;
}
}
cout << n - (lis.size() - 1);
}
