#include<bits/stdc++.h>
using namespace std;
#define rep(i,a) for(int i=0;i<a;i++)
#define pd(a,n) for(int i=0;i<n;i++)cout<<a[i]<<((i==n-1)?"\n":" ");cout<<endl;
#define pdd(a,n,m)for(int i=0;i<n;i++){for(int j=0;j<m;j++)cout<<a[i][j]<<" ";cout<<endl;}
#define mp make_pair
#define pb push_back
#define ll long long
#define int ll
//#define __int64 lng long
#define P pair<int,int>
#define PP pair<P,int>

int n;
int sum;
signed main(){
  cin>>n;
  rep(i,n){
    int now=i+1;
    if(now%3!=0&&now%5!=0)
      sum+=now;
  }
  cout<<sum<<endl;
  return 0;
}