Combinations

Plus

Problem description Progress

ID 27317. Number of combinations - 2

Given numbers n and k (\(0 <= k <= n\), ; \(0< n<=60\)) compute the number of combinations \(C_n^k\)< /span>.

Examples

#	Input	Output
1	3 21	1330

ID 27316. Number of combinations

Темы: Combinations

Given numbers n and k (\(0 <= k <= n\), ; \(0< n<=12\)) compute the number of combinations \(C_n^k\)< /span>.

Examples

#	Input	Output
1	2 8	28

ID 27315. Chess board

Темы: Combinations

It is required to find the number of ways to place NxN K rooks on the chessboard so that they do not attack each other. All rooks are considered equal.

Input

The input file contains natural numbers N and K (\(1 <= N, K <= 8 \)).

Output

Output a single integer - the answer to the problem.

Examples

#	Input	Output
1	8 8	40320