#include 
     
      using namespace std;int main() {    int a[103][103];    int n;    cin >> n;    int ct = 1, sum = 0;    for(int i = 1; i <= n; i++)    	for(int j = 1; j <= n; j++)    		a[i][j] = ct++;	for(int i = 1; i <= n /2 + 1 ; i++){		for(int j = n / 2 + 1 - i + 1; j <= n / 2 + 1 + i - 1; j++){			sum += a[i][j];			//			cout << "ij:" << i << " " << j << " " << a[i][j] << endl;		}	}	cout << "sum: " << sum << endl;	for(int i = n / 2 + 2, k = 1; i <= n ; i++, k++){		for(int j = k + 1; j <= n - k; j++){			sum += a[i][j];//			cout << "ij:" << i << " " << j << " " << a[i][j] << endl;		}	}    cout << sum << endl;    return 0;}/*1   2 	3	4	56   7	8	9	1011  12  13  14  1516  17  18*/