#include<iostream> // cin\cout\endl #include<cstdio> //scanf()\printf()\double #include<cstring> // strcpy()\strcat()\strcmp()\strlen()\memset() #include<cmath> //sqrt()\pow()\abs()\ceil()\floor()\max()\min() using namespace std; int main(){ double pi=3.1415926,r,vq; cin>>r; vq=4.0/3*pi*r*r*r; printf("%.4lf",vq); return 0; }