#include <bits/stdc++.h>

using namespace std;

long sumOfGroup(int k)
{
    int sum=0;
        if(k%2!=0)
        {
           if(k==1)
                sum=1;
           else if(k==2)
                sum=3+5;
            else if(k==3)
                sum=7+9+11;            
        }
    return sum;
}

int main() {
    int k;
    cin >> k;
    long answer = sumOfGroup(k);
    cout << answer << endl;
    return 0;
}