#include <stdio.h>

int gcd(int a, int b) {
  if (a == 0) { return b; };
  return gcd(b % a, a);
}

int lcm(int a, int b) {
  return a / gcd(a, b) * b;
}

int main(int argc, char const* argv[]) {
  unsigned long int N;
  fscanf(stdin, "%lu", &N);
  unsigned long int count = N / 3 + N / 5;
  printf("%lu\n", count * 2);
  return 0;
}