write a go solution for Description:
In this problem, we will consider complete undirected graphs consisting of n vertices with weighted edges. The weight of each edge is an integer from 1 to k.

An undirected graph is considered beautiful if the sum of weights of all edges incident to vertex 1 is equal to the weight of MST in the graph. MST is the minimum spanning tree — a tree consisting of n-1 edges of the graph, which connects all n vertices and has the minimum sum of weights among all such trees; the weight of MST is the sum of weights of all edges in it.

Calculate the number of complete beautiful graphs having exactly n vertices and the weights of edges from 1 to k. Since the answer might be large, print it modulo 998244353.

Input Format:
The only line contains two integers n and k (2<=n<=250; 1<=k<=250).

Output Format:
Print one integer — the number of complete beautiful graphs having exactly n vertices and the weights of edges from 1 to k. Since the answer might be large, print it modulo 998244353.

Note:
None. Output only the code with no comments, explanation, or additional text.