#include <bits/stdc++.h>
using namespace std;
#define int long long
#define endl '\n'
#define vi vector<int>
#define vb vector<bool>
#define pii pair<int,int>
#define mod 1000000007
#define ss second
#define ff first
#define vpii vector<pii>
#define vvi vector<vi>
#define pb push_back
#define vs vector<string>
#define all(x) x.begin(),x.end()
#define mii map<int,int>
const int inf=0x3f3f3f3f3f3f3f3f;
void print(vi &v){
    for(int i=0;i<v.size();i++)cout<<v[i]<<" ";
    cout<<endl;
}
int power(int a,int b){
    int res = 1;
    while(b!=0){
        if(b&1){
            res *= a; 
        }
        a = (a * a);
        b = (b / 2);
    }
    return res;
}
int32_t main(){
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    cout.tie(NULL);
    int t;
    t = 1;
    while(t--){
        int sum = 0,n,i;
        cin>>n;
        for(i=1;i<=n;i++){
        	if(i%3 && i%5)sum+=i;
        }
        cout<<sum<<endl;
    }
    return 0;
}