Definition 1. n!!…! = n(n−k)(n−2k)…(n mod k), if k doesn’t divide n;
n!!…! = n(n−k)(n−2k)…k, if k divides n (There are k marks ! in the both cases).
X mod Y — a remainder after division of X by Y.
For example, 10 mod 3 = 1; 3! = 3·2·1; 10!!! = 10·7·4·1.
Given numbers n and k we have calculated a value of the expression in the first definition. Can you do it as well?
contains the only line: one integer n, 1 ≤ n ≤ 10, then exactly one space, then k exclamation marks, 1 ≤ k ≤ 20.
contains one number — n!!…! (there are k marks ! here).
Problem Author: Oleg Katz
Problem Source: The 3rd high school children programming contest, USU, Yekaterinburg, Russia, March 4, 2001