#include<iostream>
#include<cstdio>
#include<cmath>
#include<cstring>
#include<string>
#include<stack>
#include<queue>
#include<vector>
#include<algorithm>
#include<iomanip>
#include<set>
#include<unordered_set>
#include<map>
typedef long long int ll;
using namespace std;
#define FOR(i,a,b) for (int i=(a);i<(b);i++)
#define REP(i,n) for (int i=0;i<(n);i++)
#define EREP(i,n) for (int i=1;i<=(n);i++)
#define ALL(a) (a).begin(),(a).end()
//#define EVEL 1

#ifdef EVEL
#define DEB(X) cout << #X << ":" <<X<<" " ;
#define TF(f) f ? cout<<"true  " : cout<<"false ";
#define END cout<<"\n";
#else
#define DEB(X) {}
#define TF(f) {}
#define END {}
#endif
const ll MOD = 1000000007;
const int INF = 2000000000;
    ll N,M,K;
    ll A[100010],B,C,X;
    bool F=true;
    ll ans=0;
    string S;
    priority_queue<ll,vector<ll>,greater<ll>> Q,W;
int main(){
    ios_base::sync_with_stdio(false);
    cin>>N;
    EREP(i,N){
        if(i%5!=0&&i%3!=0){
            ans+=i;
        }
    }
    cout<<ans<<endl;
    return 0;
}
