#include<bits/stdc++.h>
//#include<ext/pb_ds/assoc_container.hpp>
//#include<ext/pb_ds/tree_policy.hpp>

    #pragma GCC optimize("unroll-loops")
    #pragma GCC optimize("Ofast")
    #pragma GCC optimize("-O3")
    #pragma GCC optimize("no-stack-protector")
    #pragma GCC optimize("fast-math")

#define fi first
#define f first
#define se second
#define s second
#define vi_a vector<int>a;
#define p_b push_back
#define ll long long
#define ld  double
#define pll pair<ll,ll>
#define pii pair<int,int>
#define m_p make_pair
#define fast_io cin.tie(0);cout.tie(0);ios_base::sync_with_stdio(0);
#define all(x) x.begin(),x.end()
#define getfiles    ifstream cin("input.txt");ofstream cout("output.txt");
#define pw(x) (1ll << x)
#define sz(x) (ll)x.size()
#define endl "\n"
#define rall(x) x.rbegin(),x.rend()
#define len(a) (ll)a.size()
#define rep(x,l,r) for(ll x=l;x<r;x++)
//#define for(int i=0;i<n;i++) for(ll i=0;i<n;i++)
using namespace std;
//using namespace __gnu_pbds;
ld eps = (ld)1 / 1e6;
ll inf = INT_MAX, mod2 = 998244353, mod1 = 1e9 + 7;
ll sqr(ll a) { return a * a; }
ll qb(ll a) { return a * a * a; }
ll gcd(ll a, ll b) { return !a ? b : gcd(b % a, a); }
ll binpow(ll a, ll b, ll mod) { return b ? (b % 2 ? (a * (sqr(binpow(a, b / 2, mod)) % mod)) % mod : sqr(binpow(a, b / 2, mod)) % mod) : 1; }
ll binmult(ll a, ll b, ll mod) { return b ? (b % 2 ? (2 * binmult(a, b / 2, mod) + a) % mod : (2 * binmult(a, b / 2, mod)) % mod) : 0; }
/////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
//const ll to[5]={0,4,6,7,9};
//const ll N=2*1e5+1;
const ll R=1e4;
const ll to[7]={1,2,3,1,3,2,1};
const ll tx[4]={0,0,-1,1};
const ll ty[4]={-1,1,0,0};
const char rev_to[4]={'E','W','N','S'};
const ll N=1e5;
signed main(){
    fast_io;
   ll n;
   cin>>n;
   ll ans=0;
    for(ll i=1;i<=n;i++){
        if(i%3 && i%5) ans+=i;
    }
    cout<<ans;
    return 0;
}

/*



    /////

*/
