#include<bits/stdc++.h>
#define int long long
using namespace std;
inline int read()
{
	int f=1,num=0;
	char c=getchar();
	while(c<'0'||c>'9'){if(c=='-') f=-1;c=getchar();}
	while(c>='0'&&c<='9') num=num*10+c-'0',c=getchar();
	return num*f;
}
int n,k;
int ans;
signed main()
{
	freopen("quad.in","r",stdin);
	freopen("quad.out","w",stdout);
	n=read();k=(n%2?n/2+1:n/2);
	for(int i=1;i<k;i++)
	{
		for(int j=1;j<k;j++)
		{
			if(i+j+1>=n||n-i-j+2>k*2) continue;
			ans+=min(k-1,n-i-j-1)-max(1ll,n-i-j-k+1)+1;
		}
	}
	printf("%lld",ans);
	return 0;
}