#include<stdio.h>
#define PI 3.1415926
int main(){
	float R,V;
	scanf("%f",&R);
	V=4*PI*R*R*R/3;
	if(V-(int)V>=0.6){
		printf("%d",(int)V+1);
	}else{
		printf("%d",(int)V);
		
	}
	return 0;
	
}