The Number of N-k-special Sets

A set $X$ of natural numbers is called $n$-$k$-special when all of the following hold:

• every element $x \in X$ satisfies $1 \le x \le n$,
• the sum of all elements of $X$ is strictly greater than $k$,
• $X$ contains no pair of consecutive natural numbers, that is, no two elements differ by exactly $1$.

Given two natural numbers $n$ and $k$, write a program that computes the number of $n$-$k$-special sets.

The first line contains two natural numbers $n$ and $k$ separated by a single space, with $1 \le n \le 100$ and $0 \le k \le 400$.

Print one non-negative integer: the number of $n$-$k$-special sets for the given $n$ and $k$.