#include <iostream>

using namespace std;
int main()
{
	int factorialnumber = 0;
	cout<<"Please enter a number: ";
	cin>>factorialnumber;
	int zero_count = 0;
	for(int five_factor=5; five_factor<=factorialnumber; five_factor*=5)
	{
		zero_count += factorialnumber/five_factor;
	}
	cout<<"Trailing zeros of "<<factorialnumber<<"! is "<<zero_count<<endl;
}