Description

SuperSum is a function defined as: 
SuperSum(0 , n) = n, for all positive n.
SuperSum(k , n) = SuperSum(k-1 , 1) + SuperSum(k-1 , 2) + ... + SuperSum(k-1 , n), for all positive k, n.
Given k and n, return the value for SuperSum(k , n).
Constraints
-
k will be between 1 and 14, inclusive.
-
n will be between 1 and 14, inclusive.

Input

 One line with two numbers k n.

Output

 One line SuperSum(k,n).

Sample Input

1
3
2
3
4
10
10
10

Sample Output

6
10
2002
167960

HINT

Source

TopCoder