import java.util.Scanner;

public class Main {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int x = sc.nextInt();
		int s = x / 100 ;
		int g = x % 100;
		double sum = (double)(x + s + g) / 3;
		System.out.println(String.format("%.2f", sum));
	}
}
/**************************************************************
	Problem: 1618
	User: admin
	Language: Java
	Result: Accepted
	Time:674 ms
	Memory:40500 kb
****************************************************************/