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: Time Limit Exceeded)

import sys

# 許容する再帰処理の回数を変更
sys.setrecursionlimit(10 ** 5 + 10)

def rec(pos, a, dp, n, k):
    if dp[pos] != -1:
        return dp[pos]
    dp[pos] = 1
    for nxt in range(pos + 1, n):
        if abs(a[pos] - a[nxt]) <= k:
            dp[pos] = max(dp[pos], rec(nxt, a, dp, n, k) + 1)
    return dp[pos]


def acl_beginner_d():
    n, k = map(int, input().split())
    a = []
    for _ in range(n):
        a.append(int(input()))
    dp = [-1] * n
    ans = 0
    for i in range(n-1, -1, -1):
        v = rec(i, a, dp, n, k)
        ans = max(ans, v)
    print(ans)


acl_beginner_d()