#include<iostream>
#include<vector>
#include<algorithm>
using namespace std;
int main(){
    int N,count=0;
    cin >> N;
    for(int i=1;i<=N;i++){
        if(i%3==0&&i%5==0)  count+=4;
        else if(i%3==0||i%5==0) count+=2;
    }
    cout << count;
}