#include<bits/stdc++.h>
using namespace std;
#define rep(i,n) for(int i=0;i<=(int)(n);++i)
#define REP(i,n_1,n_2) for(int i=(int)(n_1);i<=(int)(n_2);++i)
#define ll long long
#define P pair<int,int>

int main(){
    int n;
    cin>>n;
    ll int sum=0;
    for(int i=1;i<=n;++i){
        if(i%3!=0 && i%5!=0)
            sum+=i;
    }
    cout<<sum<<endl;
    return 0;
}