n, k = map(int, input().split(" "))
arr = [int(x) for x in input().strip().split()]

arr.sort()

pairs = 0
i = 0
while i < n - 1:
    if arr[i + 1] - arr[i] <= k:
        pairs += 1
        i += 2
    else:
        i += 1

print(pairs)