#include <stdio.h>

int main(){

	long long N;

	scanf("%lld",&N);

	long long A, B, C;

	A = N / 3;
	B = N / 5;
	C = N / 15;

	printf("%lld\n", ((A - C) * 2) + ((B - C) * 2) + (C * 4));

	return 0;
}