#include <bits/stdc++.h>
using namespace std;
#define pb push_back
#define is insert
#define ll long long
#define V vector
#define MS multiset
#define PL pair<ll, ll>
#define F first
#define S second
#define PQ priority_queue
#define f0r(i, begin, end) for (ll i = begin; i < end; i ++)
#define For(i, end, begin) for (ll i = end; i > begin; i --)
#define all(x) x.begin(), x.end()
#define INF 1000000000000000000
#define inf 1000000000
#define MOD 998244353
#define len(x) (ll)x.size()
#define fileread(file) ifstream fin; fin.open((string)file + ".in"); ofstream fout; fout.open((string)file + ".out")
#define fastio ios_base::sync_with_stdio(0LL); cin.tie(nullptr)
template<typename T> istream& operator>>(istream& in, V<T>& a) {for(auto &x : a) in >> x; return in;};
template<typename T> ostream& operator<<(ostream& out, V<T>& a) {for(auto &x : a) out << x << ' '; return out;};
ll N, M;
V<ll> heights;
int main () {
cin >> N >> M;
f0r (i, 1, N + 1) {
ll a; cin >> a;
heights.pb(-a + i * M);
}
V<ll> dp;
f0r (i, 0, N) {
ll num = heights[i];
if (num < 0) continue;
else if (dp.empty()) dp.pb(num);
else if (num >= dp[len(dp) - 1]) dp.pb(num);
else {
ll pos = lower_bound(all(dp), num) - dp.begin();
dp[pos] = num;
}
}
cout << N - len(dp) << endl;
}
