#include <iostream>
using namespace std;
using ll = long long int;

int main(){
    ll n;
    cin >> n;
    ll ans = 0;
    ans += (((n-1)/2)*4+3) * ((n+1)/2);
    ans += ((n/2)*4+1) * ((n+2)/2);
    ans += n*2+1;
    //cerr << ans << endl;
    //cerr << (n-(1-n%2))*2+1 << " " << ((n/2)*2)*2+1 << " " << n*2+1 << endl;
    ans += ((n-(1-n%2))*2+1)*((n-1)/2);//((n/2)*2+n%2)*2+1
    ans += (((n/2)*2)*2+1)*((n-2)/2);
    if(n == 1) ans--;
    cout << ans << endl;
    return 0;
}