import bisect 
# # Binary Search module for list
# import sys
# from sys import stdin, exit, setrecursionlimit
# from collections import deque
# from collections import Counter
# from itertools import accumulate
# from heapq import heappop, heappush
# from atcoder.segtree import SegTree
# from sortedcontainers import SortedSet, SortedList, SortedDict


# input = stdin.readline
def main():
    N, D = map(int, input().split())
    A = list(map(int, input().split()))
    d = {}
    cnt = 0
    for i in range(N):
        d.setdefault(A[i], [])
        d[A[i]].append(i)
    for j in range(1, N-1):
        if A[j]-D not in d.keys() or A[j]+D not in d.keys():
            continue
        cnt_i = bisect.bisect_left(d[A[j]-D], j)
        cnt_k = len(d[A[j]+D])-bisect.bisect_left(d[A[j]+D], j)
        cnt += cnt_i*cnt_k
    print(cnt)
    

# =====================================
# mylib
# =====================================
def get_primenumbers(mx):
    """
    エラトステネスの篩
    引数mxまでの素数をリストで返す

    :param mx: 探索範囲の最大値
    """
    prime_l = [True for _ in range(mx+1)]
    prime_l[0] = False
    prime_l[1] = False
    for i in range(4, mx+1, 2):
        prime_l[i] = False
    i = 3
    while i**2<mx:
        if not prime_l[i]:
            i+=2
            continue
        for j in range(i**2, mx+1, i):
            prime_l[j] = False
        i+=2
    prime = [2]
    for i in range(3, mx+1, 2):
        if prime_l[i]:
            prime.append(i)
    return prime

main()