//teja349 #include <bits/stdc++.h> #include <vector> #include <set> #include <map> #include <string> #include <cstdio> #include <cstdlib> #include <climits> #include <utility> #include <algorithm> #include <cmath> #include <queue> #include <stack> #include <iomanip> //setbase - cout << setbase (16); cout << 100 << endl; Prints 64 //setfill - cout << setfill ('x') << setw (5); cout << 77 << endl; prints xxx77 //setprecision - cout << setprecision (14) << f << endl; Prints x.xxxx using namespace std; #define f(i,a,b) for(i=a;i<b;i++) #define rep(i,n) f(i,0,n) #define fd(i,a,b) for(i=a;i>=b;i--) #define pb push_back #define mp make_pair #define vi vector< int > #define vl vector< ll > #define ss second #define ff first #define ll long long #define pii pair< int,int > #define pll pair< ll,ll > #define sz(a) a.size() #define inf (1000*1000*1000+5) #define all(a) a.begin(),a.end() #define tri pair<int,pii> #define vii vector<pii> #define vll vector<pll> #define viii vector<tri> #define mod (1000*1000*1000+7) #define pqueue priority_queue< int > #define pdqueue priority_queue< int,vi ,greater< int > > //std::ios::sync_with_stdio(false); int main(){ std::ios::sync_with_stdio(false); ll k,ans=0,i; cin>>k; ll val=0; rep(i,k){ val+=i; } val*=2; val++; rep(i,k){ ans+=val; val+=2; } cout<<ans<<endl; return 0; }