#include <bits/stdc++.h>
using namespace std;
int main(){ 
    int i,h=0;
    cin>>i;
    for(int x=1;x<=i;x++){
        for(int y=1;y<x;y++){
            if((x+y)%3==0||(x+y)%7==0) h++;
        }
    }
    cout<<h;
}
/**************************************************************
	Problem: 1086
	User: linzihang
	Language: C++
	Result: Accepted
	Time:9 ms
	Memory:2072 kb
****************************************************************/