function FizzBuzzString(N) {
  return (Math.floor(N / 3) + Math.floor(N / 5)) * 2;
}

function Main(input) {
    n = parseInt(input);
    ans = FizzBuzzString(n);
    console.log('%d', ans);
}
// Don't edit this line!
Main(require("fs").readFileSync("/dev/stdin", "utf8"));