#include <bits/stdc++.h>
using namespace std;
int main(){
    int n,a,b;
    cin>>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: linzihang
	Language: C
	Result: Compile Error
****************************************************************/