Niebieskie ksi.eczki
IV Olimpiada Informatyczna 1996/1997
Task: LIC
Author: Wojciech Rytter
The number of n-k-special sets
III stage contest  
Source fileLIC.??? (e.g. PAS,C, CPP)
Executable fileLIC.EXE
Input fileLIC.IN
Output fileLIC.OUT

We say that a set X of natural numbers is n-k-special if:

  1. for every x belonging to the set X: 1 <= x <= n,
  2. the sum of all integers from X is greater than k,
  3. X does not contain a pair of consecutive natural numbers.

Task

Write a program that:

Input

In the first line of the text file LIC.IN there are two natural numbers n and k separated by a single space, 1 <= n <= 100, 0 <= k <= 400.

Output

In the first line of the text file LIC.OUT there should be written one non-negative integer, which equals the number of n-k-special sets for the given n and k.

Example

For the text file LIC.IN: 
5 6
the correct solution is the text file LIC.OUT 
3