#include <iostream>
using namespace std;

int N;

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