/*
Kaushal Jalan
*/
#include<bits/stdc++.h>
using namespace std;
#define int long long int
#define pb push_back
#define mp make_pair
#define F first
#define S second
#define r0 return 0;
#define f(k,i,n,j) for(ll k=i;k<=n;k=k+j)
#define cin(a) cin>>a;
#define loop int t;cin>>t;while(t--)
#define vi vector<int>
#define vii vector<long long int>
#define SORT(v) sort(v.begin(),v.end());
#define mod 1000000007
#define crap ios_base::sync_with_stdio(false);cin.tie(0);cout.tie(0);
#define endl "\n"
int min(int a,int b){
    return (a<b)?a:b;
}
int max(int a,int b){
    return (a>b)?a:b;
}
int fp(int a,int b){
    if(b==0) return 1;
    int x=fp(a,b/2);
    x=(x*x)%mod;
    if(b&1) x=(x*a)%mod;
    return x;
}
void c_p_c()
{
    crap;
#ifndef ONLINE_JUDGE
    freopen("input.txt", "r", stdin);
    freopen("output.txt", "w", stdout);
#endif
}
signed main()
{
    //c_p_c();
    int n;
    cin>>n;
    int sum=0;
    for(int i=1;i<=n;i++)
    {
        
        if(i%3==0)
        continue;
        if(i%5==0)
        continue;
        sum+=i;
    }
    cout<<sum<<endl;
}