//你不让用就不让?

import java.util.*;

public class Main{

public static void main(String[] args){
    Scanner sc = new Scanner(System.in);
    while(sc.hasNext()){
        double num = sc.nextDouble();
        double flag = 0;
        if(num > 0){
            flag = 1.0;
        }else{
            flag = -1.0;
        }
        System.out.println(flag * Double.parseDouble(String.format("%.1f", Math.exp((Math.log(Math.abs(num)) / 3)))));
    }
}

}