#include<fstream>
using namespace std;
ifstream f1 ("nrtri.in");
ofstream f2 ("nrtri.out");
int main()
 {
	int n,k,i,j,c,v[801];
	f1>>n;
	c=0;
	for (i=0; i<n; i++) {f1<<k; v[i]=k;}
	for (i=0; i<n; i++)
		for (j=i+1; j<n; j++)
			for (l=j+1; j<n; j++)
				if (v[i]+v[j]>v[l] && v[j]+v[l]>v[i]&& v[i]+v[l]>v[j]) c++;
	f2<<c;
	return 0;}