#include<bits/stdc++.h>
using namespace std;
using ll = long long;
using ld = long double;
using vi = vector<int>;
using pii = pair<int, int>;
#define sz(a) (int)(a).size()
#define all(a) (a).begin(), (a).end()
#define pb push_back
const int N = 2e5 + 5;
int n, a[N], m;
int fw[N];
ll b[N];
void update(int x, int y) {
for (; x; x -= x & -x) fw[x] = max(fw[x], y);
}
int get(int x) {
int ans = 0;
for (; x <= n; x += x & -x) ans = max(ans, fw[x]);
return ans;
}
int lis() {
vector<pair<ll, int>> c(n);
for (int i = 1; i <= n; ++i) c[i - 1] = {b[i], i};
sort(all(c));
int nxt = 1;
for (int i = 0; i < n; ++i) {
if (i > 0 && c[i].first != c[i - 1].first) nxt += 1;
b[c[i].second] = nxt;
}
int ans = 0;
for (int i = 1; i <= n; ++i) {
int x = get(b[i]) + 1;
update(b[i], x);
ans = max(ans, x);
}
return ans;
}
int main() {
cin.tie(nullptr)->sync_with_stdio(false);
cin >> n >> m;
for (int i = 1; i <= n; ++i) {
cin >> a[i];
b[i] = a[i] - 1LL * i * m;
}
cout << n - lis();
}
