#include <iostream>
#include <fstream>
using namespace std;
long n,i,x,y,z,t;
int main()
{fstream fin,fout;
fin.open("patrate2.in",ios::in);
fout.open("patrate2.out",ios::out);
x=0;y=0;z=1;t=1;fin>>n;
if (n>1)
{x=4*(n-2)*(n-2);
y=4*(n-2)*(n-2);
z=4*(2*n-2)*(2*n-2);
t=4*(2*n-2)*(2*n-2);};
fout<<x+y+z+t;
fin.close();
fout.close();
    return 0;
}