Little Petya likes points a lot. Recently his mom has presented him n points lying on the line OX. Now Petya is wondering in how many ways he can choose three distinct points so that the distance between the two farthest of them doesn't exceed d.

Note that the order of the points inside the group of three chosen points doesn't matter.

Input

The first line contains two integers: n and d (1 ≤ n ≤ 105; 1 ≤ d ≤ 109). The next line contains n integers x1, x2, ..., xn, their absolute value doesn't exceed 109 — the x-coordinates of the points that Petya has got.

It is guaranteed that the coordinates of the points in the input strictly increase.

Output

Print a single integer — the number of groups of three points, where the distance between two farthest points doesn't exceed d.

Please do not use the %lld specifier to read or write 64-bit integers in С++. It is preferred to use the cin, cout streams or the %I64d specifier.

Examples

Input

4 3
1 2 3 4


Output

4


Input

4 2
-3 -2 -1 0


Output

2


Input

5 19
1 10 20 30 50


Output

1

Note

In the first sample any group of three points meets our conditions.

In the seconds sample only 2 groups of three points meet our conditions: {-3, -2, -1} and {-2, -1, 0}.

In the third sample only one group does: {1, 10, 20}.
import sys
import string
import math
import heapq
from collections import defaultdict
from collections import deque
from collections import Counter
from functools import lru_cache
from fractions import Fraction

def mi(s):
    return map(int, s.strip().split())

def lmi(s):
    return list(mi(s))

def tmi(s):
    return tuple(mi(s))

def mf(f, s):
    return map(f, s)

def lmf(f, s):
    return list(mf(f, s))

def js(lst):
    return " ".join(str(d) for d in lst)

def jsns(lst):
    return "".join(str(d) for d in lst)

def line():
    return sys.stdin.readline().strip()

def linesp():
    return line().split()

def iline():
    return int(line())

def mat(n):
    matr = []
    for _ in range(n):
        matr.append(linesp())
    return matr

def matns(n):
    mat = []
    for _ in range(n):
        mat.append([c for c in line()])
    return mat

def mati(n):
    mat = []
    for _ in range(n):
       mat.append(lmi(line())) 
    return mat

def pmat(mat):
    for row in mat:
        print(js(row))

def main():
    _, d = mi(line())
    arr = lmi(line())

    begin = 0
    ans = 0
    for e, n in enumerate(arr):
        while n - arr[begin] > d:
            begin += 1

        # If n is the largest element of the pairs,
        # then what is the best we can do?
        elems = e - begin + 1
        if elems < 3:
            continue
        else:
            ans += (elems - 1) * (elems - 2) // 2
    print(ans)
main()
