#include<bits/stdc++.h>
using namespace std;
int main(){
	int a;
	float c;
	cin>>a;
	if(a>10){
		c=25*3*5/120.0;
		cout<<ceil(c);
		}
	if(7<a&&a<10){
		c=15*3*5/120.0;
		cout<<ceil(c);
		}
	if(3<a&&a<7){
		c=5*3*5/120.0;
		cout<<ceil(c);
	}
	
}


/**************************************************************
	Problem: 1310
	User: chensijia
	Language: C++
	Result: Accepted
	Time:12 ms
	Memory:2072 kb
****************************************************************/