//Sinhov : "Hi stalker!"
#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define pb push_back
#define mp make_pair
#define mod 1000000007
int main() {
    ios_base::sync_with_stdio(false),cin.tie(NULL),cout.tie(NULL);
    ll n,q,m,t,k,i,j,x,p,val=0,minans=LLONG_MAX,a,b,c,d,flag=1;
    cin>>k;
    ll val1=(k*(k+1))/2,val2=((k-1)*k)/2;
    val=val1*val1-val2*val2;
    cout<<val<<"\n";
    return 0;
}