#arc163d. [arc163_d]Sum of SCC

[arc163_d]Sum of SCC

Problem Statement

Consider a directed graph GG with NN vertices numbered 11 to NN that satisfies all of the following conditions.

  • GG is a tournament. In other words, GG has no multi-edges or self-loops, and for any two vertices u,vu,v of GG, exactly one of the edges urightarrowvu \\rightarrow v and vrightarrowuv \\rightarrow u exists.

  • Among the edges of GG, exactly MM are directed from a vertex with a smaller number to a vertex with a larger number.

Find the total number of strongly connected components over all such directed graphs GG, modulo 998244353998244353.

Constraints

  • 1leNle301 \\le N \\le 30
  • 0leMlefracN(N1)20 \\le M \\le \\frac{N(N-1)}{2}

Input

The input is given from Standard Input in the following format:

NN MM

Output

Print the answer.


Sample Input 1

3 1

Sample Output 1

7

Below are the three directed graphs GG that satisfy the conditions. The numbers of their strongly connected components are 3,1,33,1,3 from left to right, so the answer is 77.


Sample Input 2

6 2

Sample Output 2

300

Sample Input 3

25 156

Sample Output 3

902739687