#include <stdio.h>
#include <stdint.h>

int main(void)
{
	uint64_t num;
	scanf("%ld", &num);

	uint64_t count = 0;
	uint64_t i;
	for (i = 1; i <= num; i++) {
		if ((i % 3 == 0) && (i % 5 == 0)) {
			count += 4;	
		} else if ((i % 3 == 0) || (i % 5 == 0)) {
			count += 2;
		}
	}
	printf("%ld\n", count);

	return 0;
}