# Counting Sequences

Time Limit: 2000/1000 MS (Java/Others)

Memory Limit: 32768/65536 K (Java/Others)

## Description

For a set of sequences of integers｛a1，a2，a3，...an｝, we define a sequence｛ai1,ai2,ai3...aik｝in which 1<=i1<i2<i3<...<ik<=n, as the sub-sequence of ｛a1，a2，a3，...an｝. It is quite obvious that a sequence with the length n has 2^n sub-sequences. And for a sub-sequence｛ai1,ai2,ai3...aik｝，if it matches the following qualities: k >= 2, and the neighboring 2 elements have the difference not larger than d, it will be defined as a Perfect Sub-sequence. Now given an integer sequence, calculate the number of its perfect sub-sequence.

## Input

Multiple test cases The first line will contain 2 integers n, d（2<=n<=100000，1<=d=<=10000000） The second line n integers, representing the suquence

## Output

The number of Perfect Sub-sequences mod 9901

## Sample Input

4 2
1 3 7 5

## Sample Output

4

## Source

2010 ACM-ICPC Multi-University Training Con