P2388 Product of Factorials

Background

Not telling you...

Description

Find the number of trailing zeros in $1!\times 2!\times 3!\times 4!\times \cdots \times n!$.

Input Format

One line, a single integer $n(n\le 10^8)$.

Output Format

Output the answer, the number of trailing zeros.

Explanation/Hint

Translated by ChatGPT 5