// Page 088 - 089

import java.util.Scanner;
class Prog_7_1
{
	public static void main(String[] args)
	{
		Scanner input = new Scanner(System.in);
		int aVal;
		aVal=input.nextInt();
		double myResult;
		myResult = Half(aVal);     // method call
		System.out.println("Half of "+aVal+" is "+myResult);
	}

	private static double Half(int n)
	{
		return (double)n/2;
	}
}