#include <bits/stdc++.h>
using namespace std;
#define int long long
int n,k,a[200005], dp[200005], key[200005], tree[800020];
vector<int> b;
void update(int pos, int val, int id=1, int l=1, int r=n)
{
if (pos < l or r < pos) return;
if (l==r)
{
tree[id]=val;
return;
}
int mid=(l+r)/2;
update(pos,val,id*2,l,mid);
update(pos,val,id*2+1,mid+1,r);
tree[id]=min(tree[id*2],tree[id*2+1]);
}
int get(int u, int v , int id=1, int l=1, int r=n)
{
if (r < u or v < l) return 1e18;
if (u <= l and r <= v) return tree[id];
int mid=(l+r)/2;
return min(get(u,v,id*2,l,mid),get(u,v,id*2+1,mid+1,r));
}
signed main()
{
fill(tree,tree+800010,1e18);
cin>>n>>k;
n+=2;
for (int i = 2; i < n; i++) cin>>a[i];
for (int i = 1; i <= n; i++)
{
key[i]=a[i]-i*k;
b.push_back(key[i]);
}
sort(b.begin(),b.end());
for (int i = 1; i <= n; i++) key[i]=lower_bound(b.begin(),b.end(),key[i]) - b.begin() + 1;
dp[n]=0;
update(key[n],0+n-1);
for (int i = n-1; i > 0; i--)
{
// for (int i = 1; i <= 4*n; i++) cout<<tree[i]<<' ';cout<<endl;
int cur=get(1,key[i]);
dp[i]=cur-i;
update(key[i],dp[i]+i-1);
// cout<<cur<<' '<<dp[i]<<endl;
}
cout<<dp[1];
}
