#include<stdio.h>
main(){
  int i,d,s;
  while(scanf("%d",&d)!=EOF){
    s=0;
    for(i=0;i<600/d;i++){
      s+=(d*((d*i)*(d*i)));
    }
    printf("%d\n",s);
  }
  return 0;
}
#include<bits/stdc++.h>

using namespace std;
int main()
{
	double r;
	cin>>r;
	cout<<2*r*M_PI;
}