题目描述
Problem Statement
Given a positive integer N, find the number, modulo 998244353, of subsets S of ${1, 2, \ldots, N$} that satisfy the following condition.
- Every positive integer at most N can be represented as the sum of some distinct elements of S, and there are at most two such representations.
Input
Input is given from Standard Input in the following format:
N
Output
Print the answer.
Constraints
- $1 \leq N \leq 1500$
Sample Input 1
3
Sample Output 1
2
The subsets {1,2} and {1,2,3} satisfy the condition.
Sample Input 2
5
Sample Output 2
5
Sample Input 3
1000
Sample Output 3
742952024
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
样例输出
2