#include<stdio.h>
#include<math.h>
int main(){
    double r;
    double s;
    double pi = 3.1415926;
    while(scanf("%lf",&r) != EOF){
      s = 4*pi*pow(r,3)/3;//圆的体积公式
      s = floor(s+0.5);//四舍五入
      printf("%.0lf\n",s); 
    }
}