#include <bits/stdc++.h>

using namespace std;

typedef long long ll;

ll f(int x){
    //1+3+...+x
    return (ll)(x+1)*(x+1)/4;
}
ll f(ll x,ll y){
    //x+(x+2)+...+y
    //printf("f %lld %lld\n",x+y,y-x+2);
    return (ll)(x+y)/2*((y-x+2)/2);
}
ll g(ll x){
    //1+2+...+x
    return (ll)x*(x+1)/2;
}

int main() {
    int k;
    scanf("%d",&k);
    if(k==1){
        printf("1");
        return 0;
    }
    ll r=g(k);
    r=r*2-1;
    ll l=g(k-1);
    l=l*2-1;
    l+=2;
    //printf("%lld %lld\n",l,r);
    printf("%lld",f(l,r));
    return 0;
}