#include<iostream>
using namespace std;
int main(){
	int a,b,n;
	cin>>n;
	n=n/2;
	if(n%2==0){
		a=n/2;
		b=n/2;
	}else{
		a=(n+1)/2;
		b=(n-1)/2;
	}
	n=a*b;
	cout<<n;
}
/**************************************************************
	Problem: 1356
	User: panyuchen
	Language: C++
	Result: Accepted
	Time:9 ms
	Memory:2072 kb
****************************************************************/