import math
n,c=map(int,input().split())
a=list(map(int,input().split()))
sum=0
for i in range(n-1):
    for j in range(0,n-i-1):
        if a[j]>a[j+1]:
            a[j],a[j+1]=a[j+1],a[j]
for i in a:
    if a[n-1]-i<c:
        break
    j=n//2
    l=0
    r=n
    while n>j>0 and a[j]>=c:
        if a[j]-i>c:
            r=j-1
        elif a[j]-i<c:
            l=j+1
        else:
            sum+=a.count(a[j])
            break 
        j=(l+r)//2
print(sum)