//IncubatorMan
#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp> 
#include <ext/pb_ds/detail/standard_policies.hpp>
using namespace __gnu_pbds;
using namespace std;
char gap = 32;
template<typename T> 
ostream& operator<<(ostream &os, const vector<T> &v) { 
    os << '{'; 
    for (const auto &x : v) os << gap << x;
        return os << '}'; 
}
template<typename A, typename B> 
ostream& operator<<(ostream &os, const pair<A, B> &p) {
        return os << '(' << p.first << gap << p.second << ')';
}

template <class T>
void read(T &x) {
    char c;
    for (c = getchar(); c < '0' || c > '9'; c = getchar())
        ;
    for (x = 0; c <= '9' && c >= '0'; c = getchar()) x = x * 10 + (c & 15);
}
#define ll long long 
#define lll __int128_t
#define pb push_back
#define mp make_pair
typedef pair < int,int> ii;
typedef vector<ii> vii;
typedef vector<ll>vl;
typedef vector<int> vi;
typedef vector<vi> vvi;
typedef tree<
int,
null_type,
less<int>,
rb_tree_tag,
tree_order_statistics_node_update>
ordered_set;
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());

void solve(){
    ll n;
    read(n);
    ll ans =0;
    for(ll i=1;i<=n;i++){
        if(i%3==0 | i%5==0) continue;
        ans += i;
    }
    cout<<ans<<endl;
}

int main(){
    ios_base::sync_with_stdio(false);
    cin.tie(0);
        int test=1;
        //read(test);
        while(test--){
            solve();
        }
    return 0;
}