import java.util.Scanner;

public class Main {

	public static void main(String[] args) {
		// TODO Auto-generated method stub
		Scanner sc = new Scanner(System.in);
		double a = sc.nextDouble();
		if(a > 0){
			System.out.println(String.format("%.2f", a));
		}else{
			a = -1 * a;
			System.out.println(String.format("%.2f", a));
		}
	}

}
/**************************************************************
	Problem: 1676
	User: admin
	Language: Java
	Result: Accepted
	Time:747 ms
	Memory:40452 kb
****************************************************************/