luogu#P2235. [HNOI2002] Kathy函数
[HNOI2002] Kathy函数
Problem Description
Tiger likes math very much, so he joined the school's extracurricular math club. In the club, the teacher introduced the Kathy function to Tiger, which is defined as:
$$\left\{ \begin{aligned} &f(1)=1\\ &f(3)=3\\ &f(2n)=f(n)\\ &f(4n+1)=2f(2n+1)-f(n)\\ &f(4n+3)=3f(2n+1)-2f(n) \end{aligned} \right.$$Tiger became very interested in the Kathy function, and through studying he found that many numbers satisfy .
Given a number , he wants you to find the number of positive integers such that , where .
Input Format
The input contains a single line with an integer .
Output Format
Output a single integer: the number of positive integers with that satisfy .
5
3
Hint
Constraints
For all testdata, it is guaranteed that .
Translated by ChatGPT 5