#0004BB

O-Loto

Klipan is keen to pay Loto ticket streaming to win Katica (main prize of 64 billion Europounds) even he no idea of howmany ways is possible to take K numbers from set of N different numbers. Help him to solve this dilema.


Image: loto

InputIn first and only row of standard input are integers K and N separated by empty space. (1 <= K <= N <= 64)

OutputIn first and only row of standard output write number pf ways described above.

NOTICE: Result will be less then 2^64.



Example 1:

Input:

4 4

Output:

1



Example 2:

Input:

5 10

Output:

252



Example 3:

Input:

5 30

Output:

142506


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