#include<stdio.h>
int main(){
	unsigned long long int n,r,i;
	scanf("%llu",&n);
	r=n/15*16;
	n%=15;
	for(i=1;i<=n;i++){
		if(i%3==0)r+=2;
		if(i%5==0)r+=2;
	}
	printf("%llu",r);
	return 0;
}