P1806 Running

Description

Passerby A plans to run $n$ laps to exercise. He intends to finish in multiple sessions ($\gt 1$), running a positive integer number of laps each time, then resting before continuing. To effectively improve his fitness, he decides that the number of laps he runs each time must be greater than the previous time. Assuming he has run $0$ laps at the start, how many ways are there for him to finish these $n$ laps?

Input Format

A single line containing an integer $n$.

Output Format

A single integer representing the number of ways to finish the $n$ laps.

Explanation/Hint

#### Constraints For $100\%$ of the testdata, it is guaranteed that $5 \le n \le 500$. Translated by ChatGPT 5