#include<stdio.h>
int main(void)
{
 double x;
 double y;
 scanf("",&x);
 y=3*x*x*x-7*x*x+9;
 printf("%f",y);
 return 0;
}



잘못된게 없어보이는데 ㅠㅠㅠㅠㅠ;