// yukicoder 311 (http://yukicoder.me/problems/848)
#include<cstdio>

typedef long long ll;

ll N;

int main()
{
	scanf( "%lld", &N );

	ll n15 = N/15, n3 = N/3, n5 = N/5;

	printf( "%lld\n", n15*4+(n3-n15)*2+(n5-n15)*2 );

	return 0;
}