D. Count the Arraystime limit per test2 secondsmemory limit per test512 megabytesinputstandard inputoutputstandard outputYour task is to calculate the number of arrays such that:  each array contains n elements;  each element is an integer from 1 to m;  for each array, there is exactly one pair of equal elements;  for each array a, there exists an index i such that the array is strictly ascending before the i-th element and strictly descending after it (formally, it means that a_j < a_{j + 1}, if j < i, and a_j > a_{j + 1}, if j \ge i). InputThe first line contains two integers n and m (2 \le n \le m \le 2 \cdot 10^5).OutputPrint one integer — the number of arrays that meet all of the aforementioned conditions, taken modulo 998244353.ExamplesInput
3 4
Output
6
Input
3 5
Output
10
Input
42 1337
Output
806066790
Input
100000 200000
Output
707899035
NoteThe arrays in the first example are:  [1, 2, 1];  [1, 3, 1];  [1, 4, 1];  [2, 3, 2];  [2, 4, 2];  [3, 4, 3]. 
3 4

6 
['combinatorics', 'math', '*1700']