x1+...+xk = n

Input

Two positive integers $k$ and $n$ (k \le n \le 100).

Output

Print the number of positive integer solutions to the given equation. It is known that the answer does not exceed 10^{18}.

Examples

There are $3$ positive integer solutions to the equation x_1 + x_2 + x_3 = 4:

• (1,1,2)

• (1,2,1)

• (2,1,1)