#include<iostream>
#define rep(i,n) for(int i=0;i<n;i++)
using namespace std;
typedef long long ll;
int main()
{
    int n;
    cin>>n;
    ll sum=0;
    for (int i = 1; i <=n ; i++)
    {
        if(i%3==0 && i%5==0) continue;
        else if(i%3==0) continue;
        else if(i%5==0) continue;
        else sum+=i;
    }
    cout<<sum<<endl;

    return 0;
}