/*
 KUNAL RAUT (ZUKONIT14)  :- "DO WHAT YOU LIKE!"
 -PICT,PUNE! :)
 */
#include<bits/stdc++.h>
using namespace std;
#define ll long long
#define int long long
#define ld long double
#define pb push_back
#define mp make_pair
#define fi first
#define se second
#define mod 1000000007
#define mod9 1000000009
#define pi 3.1415926535
#define MAXN 1000005
#define N 1000001
#define MAX2N 1*1000 + 10
#define all(v) v.begin(), v.end()
#define ms(s, n) memset(s, n, sizeof(s))
#define prec(n) fixed<<setprecision(n)
#define forci(p,n) for(ll i=p;i<(ll)n;i++)
#define forcj(p,n) for(ll j=p;j<(ll)n;j++)
#define bolt ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0);
#define bits(a) __builtin_popcount(a)
#define test ll t;cin>>t;for(ll testi=1;testi<=t;testi++)
#define djokovic  freopen("input00.txt", "r", stdin);freopen("output00.txt", "w", stdout);
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);}
ll expo(ll x, ll y) {
    ll res = 1; x = x % mod; while (y > 0) {
        if (y & 1)res = (1ll * res * x) % mod;
        y = y >> 1; x = (1ll * x * x) % mod;
    } return res;
}
ll ncr(ll n, ll r) { ll res = 1; if (r > n - r)r = n - r; for (ll i = 0; i < r; i++) {  res *= n - i;  res /= i + 1; } return res;}
ll max(ll a, ll b) {return (a > b) ? a : b;}
bool prime(ll n) {ll i; for (i = 2; i <= sqrt(n); i++) {if (n % i == 0)return false;} return true;}
bool sortbysec(const pair<ll, ll> &a, const pair<ll, ll> &b)
{   if (a.second == b.second)
        return a.first < b.first;
    return (a.second < b.second);
}
//https://www.youtube.com/watch?v=WTJSt4wP2ME

ll rr[] = {0, 1, 1, 1, 0, -1, -1, -1,};
ll cc[] = {1, 1, 0, -1, -1, -1, 0, 1};
ll n, m, x, y, k, a[MAXN], p[MAXN];
void solve()
{
    cin >> n; ll sum = 0;
    forci(1, n + 1)
    if (i % 3 && i % 5)  sum += i;
    cout << sum;
}
signed main()
{
    bolt;
    //djokovic;
    solve();
}


