Significant inversions

Consider an arbitrary sequence of numbers x[1], x[2], ..., x[n]. A pair of indices (j, k) is called an inversion (violation of the order), if j < k and x[j] > x[k]. For any non-negative integer t a pair of indices (j, k) is called a t-significant inversion, if j < k and x[j] > x[k] + t.

Count the number of t-significant inversions in the sequence x[1], x[2], ..., x[n].

Input

The first line contains two integers n (1 ≤ n ≤ 50000) and t (0 ≤ t ≤ 10^9). The second line contains integers x[1], x[2], ..., x[n], not greater than 10^9 by absolute value.

Output

Print the number of t-significant inversions in the sequence x[1], x[2], ..., x[n].

Examples