#include <bits/stdc++.h>
using namespace std;
#define forn(i, n) for(ll i = 0; i < (n); ++i)
#define for1(i, n) for(ll i = 1; i <= (n); ++i)
#define chmin(a, b) ((a) = min(a, b))
#define all(x) (x).begin(), (x).end()
#define dbg(x) cout << #x << " = " << (x) << endl;
using ll = long long;
using vi = vector<int>;
const int oo = 1e7;
void compress(vi& v)
{
sort(all(v));
v.erase(unique(all(v)), v.end());
}
const int MAXN = 2e5 + 2;
ll n, m;
int a[MAXN];
vi v;
int rnk(int x) {
return lower_bound(all(v), x) - v.begin();
}
int N;
class SegmentTree
{
vi info;
#define set_m int m = l + (r - l) / 2;
#define left l, m, 2*p
#define right m+1, r, 2*p+1
#define in_range (i <= l and r <= j)
void up(int p) { info[p] = min(info[2*p], info[2*p+1]); }
public:
SegmentTree() = default;
SegmentTree(int n) { N = n + 3; info = vi(4*N, oo); }
void set(int k, int x, int l=0, int r=N, int p=1)
{
if (l == r) { info[p] = x; return; }
set_m;
if (k <= m) set(k, x, left);
if (k > m) set(k, x, right);
up(p);
}
int query(int i, int j, int l=0, int r=N, int p=1)
{
if in_range return info[p];
set_m;
int ans = oo;
if (i <= m) chmin(ans, query(i, j, left));
if (j > m) chmin(ans, query(i, j, right));
return ans;
}
void update(int k, int x)
{
int prv = query(k, k);
if (x < prv) set(k, x);
}
void print()
{
cout << "[ ";
for (int i = 0; i <= N; ++i) cout << query(i, i) << ' ';
cout << "]\n";
}
};
SegmentTree st;
#define mret return mem[i] =
int mem[MAXN];
int f(int i)
{
if (i == -1) return 0;
if (mem[i] != -1) return mem[i];
// int ans = oo;
// for (int j = i; j >= 0; --j)
// if (a[j] - j * m >= a[i + 1] - (i + 1) * m)
// chmin(ans, f(j - 1) - j);
// mret i + ans;
int r = rnk(a[i + 1] - (i + 1) * m);
int res = st.query(r, N);
res = i + res;
st.update(r, res - (i + 1));
// dbg(i + 1) dbg(a[i + 1] - (i + 1) * m) dbg(r)
// st.print();
mret res;
}
int main()
{
cin >> n >> m;
for1(i, n) cin >> a[i];
forn(j, n+3) v.push_back(a[j] - j * m);
compress(v);
st = SegmentTree(n);
st.set(rnk(0), 0);
// st.print();
forn(i, n+2) mem[i] = -1;
forn(i, n+1) f(i);
cout << f(n);
}
