Cow Sets

Farmer Ran's N cows (1 <= N <= 34) are numbered 1..N and lined up in a row. Cow i
has been assigned the ID number C_i (-10,000,000 <= C_i <= 10,000,000). FR
wants to pick some subset of the cows (possibly including the empty set) to
play Frisbee. To give his cows a challenge, he will only allow a set of
cows to play if the sum of their ID numbers is between A and B
(-500,000,000 <= A <= B <= 500,000,000), inclusive. 

Help FR find the number of sets of cows that can play Frisbee according to these 
constraints!

PROBLEM NAME: cowset

INPUT FORMAT:

* Line 1: Three space-separated integers: N, A, and B.

* Lines 2..N+1: Line i+1 contains the single integer C_i.

SAMPLE INPUT:

3 -1 2
1
-2
3

OUTPUT FORMAT:

* Line 1: A single integer representing the number of subsets of cows
        that can play Frisbee. (It may be necessary to use 64-bit
        integers when calculating the result.)

SAMPLE OUTPUT:

5