#include<iostream>
#include<string>
#include<queue>
#include<vector>
#include<cassert>
#include<random>
#include<set>
#include<map>
#include<cassert>
#include<unordered_map>
#include<bitset>
#include<numeric>
#include<algorithm>
using namespace std;
typedef long long ll;
const int inf=1<<30;
const ll INF=1LL<<62;
typedef pair<int,ll> P;
typedef pair<int,P> PP; 
const ll MOD=998244353;


int main(){
    ll N;
    cin>>N;

    ll ans=0;

    for(int i=1;i<=N;i++){
        if(i%3==1){
            ans+=i;
        }else if(i%3==2){
            ans+=1LL*i*i;
        }else{
            ans+=1LL*i*i*i;
        }
    }
    cout<<ans<<endl;
}