#include <bits/stdc++.h>
#define ll long long int
using namespace std;

int main() {
  ll n, sum=0;
  cin >> n;

  for(int i=1; i<=n;i++){
    if(i%3==0 && i%5==0) {
      continue;
    } else if (i%3==0){
      continue;
    } else if (i%5==0){
      continue;
    } else {
      sum+=i;
    }
  }
  cout << sum;
}