#include<bits/stdc++.h>
using namespace std;
int main(){
    int n,w,s;
    cin>>n;
    w=n/4;
    s=w*w;
    cout<<s;
	return 0;
}

/**************************************************************
	Problem: 1420
	User: zhujiayi
	Language: C++
	Result: Wrong Answer
****************************************************************/