#include<stdio.h>
unsigned long long int n,i,c;
int main()
{
	scanf("%ld",&n);
	for(i=3;i<=n;i++){
		if(i%3==0&&i%5==0){
			c+=4;
		}else if(i%5==0){
			c+=2;
		}else if(i%3==0){
			c+=2;
		}
	}
	printf("%ld",c);
	return 0;
}