#include <bits/stdc++.h>
using namespace std;

typedef long long ll; // -9,223,372,036,854,775,808 から 9,223,372,036,854,775,807

template <class T> using vec = std::vector<T>;
template <class T> using vec2 = vec<vec<T>>;
template <class T> using vec3 = vec<vec<vec<T>>>;

#define DEBUG

void solve(long long N){
    ll res = 0;
    for(int i=1; i <= N; i++){
        if(i % 3 != 0 && i % 5 != 0){
            res += i;
        }
    }
    cout << res << endl;
}

// Generated by 1.1.6 https://github.com/kyuridenamida/atcoder-tools  (tips: You use the default template now. You can remove this line by using your custom template)
int main(){
    long long N;
    scanf("%lld",&N);
    solve(N);
    return 0;
}
