#include<bits/stdc++.h>

#define ll long long
#define endl "\n"
#define mp(x,y) make_pair(x,y)
#define pb(x) push_back(x)
#define f first
#define s second
#define vecll vector<ll>
#define pairll pair<ll,ll>
#define vecpairll vector<pair<ll,ll>>
#define mapllll map<ll,ll>
#define mapstrll map<string,ll>
#define mapllvecll map<ll,vecll>
#define setll set<ll>
#define fio ios_base::sync_with_stdio (false); cin.tie (NULL); cout.tie(NULL);

using namespace std;

ll const N=1e5+5;
ll const inf=1e18+5;
ll const MOD=1e9+7;

ll t,n,m,x,y,z,w,k;

int main()
{
    fio

    cin>>n;

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

