import java.util.*;
import javax.swing.*;
public class Factrial
{
	
	public static void main(String[] args)
	{
		int num = Integer.parseInt(JOptionPane.showInputDialog(" Insert integre number"));
		System.out.println("Number = "+ num );
		FactZeros(num);
		
		
		System.exit(0);
	}
	
	private static void FactZeros(int n)
	{    int NumOfZeros = 0;
		if (n< 5)
			System.out.println("NumOfZeros = "+NumOfZeros);
		else {
			int num = n;
			do{
				num = num - 5;
				NumOfZeros++;
				
			}while(num >= 5);
			System.out.println("NumOfZeros = "+NumOfZeros);
			
		}
		
	}
}