#include <bits/stdc++.h>
#define REP(i, n) for(int i=0;i<int(n);++i)
using namespace std;
template<class A>void pr(A a){cout << a << endl;}
template<class A,class B>void pr(A a,B b){cout << a << " "  ;pr(b);}
template<class A,class B,class C>void pr(A a,B b,C c){cout << a << " " ;pr(b,c);}
template<class A,class B,class C,class D>void pr(A a,B b,C c,D d){cout << a << " " ;pr(b,c,d);}
typedef long long ll;
typedef pair<ll, ll> l_l;
typedef pair<int, int> i_i;
int INF=numeric_limits<int>::max();
// for(int j=0;j<N;++j) {}

int main(void) {
  int n;cin>>n;
  ll sum=0;
  for(int i=1;i<=n;++i) {
    if(i%3!=0&&i%5!=0) {
      sum+=i;
    }
  }
  pr(sum);
  return 0;
}
