import java.util.Scanner;

public class Polynomial $\{$

public static void main$($String$[]$ args$)\{$

Scanner scnr $=$ new Scanner$($System$.$in$)$;

double w;

double k;

w $=$ scnr$.$nextDouble$()$;

k $=-(2\mathrm{.}0*$ w $*$ w$)-(0\mathrm{.}5*$ w$)-7\mathrm{.}0$;

$\}$

$\}$