#include <bits/stdc++.h>

using namespace std;

long sumOfGroup(int k) {
    // Return the sum of the elements of the k'th group.
    int a[4][4]={{1},{3,5},{7,9,11},{13,15,17,19}};
    int sum=0;
    for(int i=k-1;i<k;i++)
    {
     for(int j=0;j<=i;j++)
     {
         sum+=a[i][j];
     }
    }
    return sum;
}

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