#include <stdio.h>

int main(void)
{
	long long unsigned int num, i, count;
	count = 0;
	
	scanf("%lld", &num);
	
	for (i = 1; i <= num; i++) {
		if ((i % 3 == 0) && (i % 5 == 0)) {
			count += 4;
		} else if (i % 3 == 0) {
			count += 2;
		} else if (i % 5 == 0) {
			count += 2;
		}
	}
	
	printf("%lld\n", count);
	
	return 0;
}