Problem:
Score : 400 points

Problem Statement

You are given a sequence A_1, A_2, ..., A_N and an integer K.

Print the maximum possible length of a sequence B that satisfies the following conditions:

B is a (not necessarily continuous) subsequence of A.

For each pair of adjacents elements of B, the absolute difference of the elements is at most K.

Constraints

1 \leq N \leq 300,000

0 \leq A_i \leq 300,000

0 \leq K \leq 300,000

All values in input are integers.

Input

Input is given from Standard Input in the following format:

N K
A_1
A_2
:
A_N

Output

Print the answer.

Sample Input 1

10 3
1
5
4
3
8
6
9
7
2
4

Sample Output 1

7

For example, B = (1, 4, 3, 6, 9, 7, 4) satisfies the conditions.

It is a subsequence of A = (1, 5, 4, 3, 8, 6, 9, 7, 2, 4).

All of the absolute differences between two adjacent elements (|1-4|, |4-3|, |3-6|, |6-9|, |9-7|, |7-4|) are at most K = 3.

Solution in PyPy3 (7.3.0) (judge verdict: Accepted)

from copy import *

def init(N,node,unit,func):
  n=1
  while n<N:
    n<<=1
  for i in range(n*2-1):
    if len(node)<=i:
      node.append(deepcopy(unit))
    else:
      node[i]=deepcopy(unit)
  node.append(func)
  node.append(unit)
  node.append(n)

def upd(node,x,a):
  y=node[-1]+x
  node[y-1]=a
  while y>1:
    y=y>>1
    node[y-1]=node[-3](node[(y<<1)-1],node[y<<1])

def query(node,l,r):
  x,y=l,r
  z=node[-1]-1
  r=node[-2]
  while True:
    if x==y:
      return r
    if x&1:
      r=node[-3](r,node[x+z])
      x+=1
    if y&1:
      r=node[-3](r,node[y+z-1])
    x>>=1
    y>>=1
    z>>=1
    if z==0:
      return r

def bis_min_k(node,k,cond):
  x=k+1
  while True:
    if node[-1]<=x:
      return x-node[-1]
    if cond(node[(x<<1)-1]):
      x=x<<1
    else:
      x=(x<<1)+1

def bis_min(node,l,r,cond):
  x,y=l,r
  z=node[-1]-1
  for i in range(30):
    if x+(1<<i)>y:
      break
    if x&(1<<i):
      if cond(node[z+(x>>i)]):
        return bis_min_k(node,z+(x>>i),cond)
      x+=(1<<i)
    if z==0:
      break
    z>>=1
  for i in range(29,-1,-1):
    if i and ((node[-1]-1)>>(i-1))==0:
      continue
    if x+(1<<i)>y:
      continue
    if (y-x)&(1<<i):
      if cond(node[((node[-1]-1)>>i)+(x>>i)]):
        return bis_min_k(node,((node[-1]-1)>>i)+(x>>i),cond)
      x+=(1<<i)
  return node[-1]

N,K=map(int,input().split())
A=0
X=[]
init(300001,X,0,lambda x,y:max(x,y))
for i in range(N):
  A=int(input())
  upd(X,A,query(X,max(0,A-K),min(300001,A+K+1))+1)
print(X[0])