//数学，没化简，直接用
#include <cstdio>
#include <iostream>
using namespace std;
int main() {
int n;
while (scanf("%d", &n) != EOF) {
int s = n * n * n;
int ans = (s-4)*4 + 6*(n-2)*(s-5) + 3*(n-2)*(n-2)*(s-6) + (n-2)*(n-2)*(n-2)*(s-7)/2;
printf ("%d\n", ans);
}
return 0;
}