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