                   /**Bismillahir Rahmanir Rahim.**/
/*
         Md.Fagun Molla
         18ICTCSE006
         BSMRSTU(SHIICT)
*/
#include <bits/stdc++.h>
using namespace std;
#define  gcd(a,b)         __gcd(a,b)
#define  lcm(a,b)         (a*b)/gcd(a,b)
#define  ll               long long
#define  vi               std::vector<int>
#define  pb               push_back
#define  MAX              100007
#define  End              return 0;
#define                   pi acos(-1)


int main () {
    ios_base::sync_with_stdio(false); cin.tie(0);cout.tie(0);
    int n;
    cin>>n;
    ll s=0;
    for(int i=1; i<=n; i++){
        if(i%3!=0 && i%5!=0)
            s+=i;
    }
    cout<<s<<endl;
    End
}
/* pray for me
Do before die
*/
