## ACSL '09 Practice P3 - Zeroes

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Points: 10
Time limit: 1.0s
Memory limit: 16M

Problem type
Allowed languages
Assembly, Brain****, C, C++, COBOL, Forth, Fortran, Java, Lua, Prolog, Text, Turing
##### ACSL Practice 2009

The factorial of a positive integer , written as , is the product of the first positive integers. That is,

Given a positive integer , find the number of zeros in the decimal representation of . Of course, leading zeros should not be counted. (Note that decimal representation means base ten representation.)

Example 1. There are zeros in the decimal representation of .

Example 2. There are zeros in the decimal representation of .

Example 3. There is no zero in the decimal representation of .

#### Input Specification

The input contains a single positive integer .

#### Output Specification

The number of zeros in the decimal representation of .

#### Sample Input 1

20

#### Sample Output 1

7

#### Sample Input 2

7

#### Sample Output 2

2

#### Sample Input 3

4

#### Sample Output 3

0