#include <iostream>
#include <algorithm>
#include <string>
#include <cstdio>
#include <vector>
#include <map>
#include <queue>
#include <set>
#include <cmath>
#include <functional>
#include <iomanip>
using namespace std;
#define reps(i,s,n) for(int i = s; i < n; i++)
#define rep(i,n) reps(i,0,n)
#define Rreps(i,n,e) for(int i = n - 1; i >= e; --i)
#define Rrep(i,n) Rreps(i,n,0)
#define ALL(a) a.begin(), a.end()
#define endl "\n"
#define fi first
#define se second
typedef long long ll;
#define traceV(v) for(auto x:v)cout<<x<<" ";cout<<endl
#define traceM(mp) for(auto x:mp)cout<<x.first<<" "<<x.second<<endl
#define MOD 1000000007
ll gcd(ll a,ll b){if(b==0)return a;return gcd(b,a%b);}
ll lcm(ll a,ll b){return a/gcd(a,b)*b;}

int main(){
  cin.tie(0);
  ios::sync_with_stdio(false);

  ll N; cin>>N;

  ll res = 0;
  reps(i,1, N+1) {
    if(i%3==0 || i%5==0)continue;
    else res+=i;
  }
  cout<<res<<endl;

  return 0;
}
