#include<iostream.h>
#include<fstream.h>
int comb(int n)
{int a=1,c=1,i;
	for(i=2;i<=n;i++)
a=a*i;
	for(i=1;i<=n-2;i++)
		c=c*i;
return a/(2*c);}

int main()
{int a,n,i,k=0,z=0;
ifstream f("fractii.in");
ofstream h("fractii.out");
f>>n;
a=2*(n-1)+1;
	for(i=3;i<=n;i=i+2)
		k++;
	for(i=2;i<=n;i=i+2)
	z++;
	h<<a+2*k*z+comb(k)*2;
	
	
	return 0;}