#include <bits/stdc++.h>
using namespace std;
int main(){
	int a;
	float b;
 	cin>>a;
 	if(a>10){
 		b=25*3*5/120.0;
 		cout<<ceil(b);
 		}
 	if(a>=7&&a<=10){
 		b=15*3*5/120.0;
 		cout<<ceil(b);
 		}
 	if(a<=6&&a>=3){
 		b=5*3*5/120.0;
 		cout<<ceil(b);
 		}
 	
 	
 	
 	
 	
 	
}
/**************************************************************
	Problem: 1310
	User: zhuangwenya
	Language: C++
	Result: Accepted
	Time:11 ms
	Memory:2072 kb
****************************************************************/