题目描述
Problem Statement
Given are integers N and M.
How many sequences A of N integers satisfy the following conditions?
- $1 \leq A_i \leq M \left(i = 1, 2, \ldots, N\right)$
- A_{i+1} is a multiple of $A_i. \left(i = 1, 2, \ldots, N - 1\right)$
Since the answer can be enormous, report it modulo 998244353.
Input
Input is given from Standard Input in the following format:
N M
Output
Print the answer.
Constraints
- All values in input are integers.
- $1 \leq N \leq 2 \times 10^5$
- $1 \leq M \leq 2 \times 10^5$
Sample Input 1
3 4
Sample Output 1
13
Some of the sequences A satisfying the conditions follow:
- $A = \left(1, 1, 4\right)$
- $A = \left(3, 3, 3\right)$
- $A = \left(1, 2, 4\right)$
Sample Input 2
20 30
Sample Output 2
71166
Sample Input 3
200000 200000
Sample Output 3
835917264
输入格式
见题面 Input 部分
输出格式
见题面 Output 部分
样例输入
3 4
样例输出
13