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

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