#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
template<class T> inline bool chmax(T& a, T b) { if (a < b) { a = b; return true; } return false; }
template<class T> inline bool chmin(T& a, T b) { if (a > b) { a = b; return true; } return false; }
#define all(x) (x).begin(),(x).end()
#define pll pair<ll,ll>
#define pii pair<int,int>
#define rep(i,n) for(int i=0;i<n;i++)
#define For(i,a,b) for(int i=a;i<b;i++)
#define sz(x) ((ll)(x).size())
#define pb push_back
#define mp make_pair
#define bit(n) (1LL<<(n))
#define F first
#define S second
#define debug(x) cerr << x << endl
#define Complex complex<double>
int dx[4]={1,0,-1,0};
int dy[4]={0,1,0,-1};
const ll INF = 1LL<<60;
const ll mod = (int)1e9 + 7;

int main() {
    int n;
    cin >> n;
    ll sum=0;
    rep(i,n){
        ll x=i+1;
        if(x%3 && x%5)sum+=x;
    }
    cout << sum;

    
}