#include<bits/stdc++.h>
using namespace std;
int main(){
	int a,b,c;
	cin>>a;
	b=a/30;
	if(a%30>0){
		c=b+1;
	}else c=b;
	cout<<c;
}
/**************************************************************
	Problem: 1632
	User: toughuatao1
	Language: C++
	Result: Accepted
	Time:8 ms
	Memory:2072 kb
****************************************************************/