#include <iostream>
#include <iomanip>
#include <cmath>

using namespace std;

int main(){
    int n;
    cin>>n;
    int i,j,s=0;
    for(i=1;i<n;i++){
    	for(j=i+1;j<=n;j++){
    		if((i+j)%3==0||(i+j)%7==0){
    			s=s+1;
			}
		}
	}cout<<s<<endl;
}
/**************************************************************
	Problem: 1086
	User: admin
	Language: C++
	Result: Accepted
	Time:9 ms
	Memory:2072 kb
****************************************************************/