#include <stdio.h>

int main(void)
{
	int n;
	int i;
	int zz;
	int sum = 0;
	
	scanf("%d", &n);
	
	zz = (n / 3) + (n / 5);
	
	sum += (zz) * 2;
	
	printf("%d\n", sum);
	
	return 0;
}