Trailing Zeros

Given a number, find the number of trailing zeros in its factorial.

Input Specification

A single integer N (1 ≤ N ≤ 1000).

Output Specification

Print a single integer, the number of trailing zeros.

Sample Input

1. 10

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Output for Sample Input

1. 2

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Sample Explanation

10! = 3 628 800 has 2 zeros at the end.