#include <bits/stdc++.h>
using namespace std;
int n;
int main (){
	cin>>n;
	int n1=n,n2=n,n3=n;
	int a=0,b=0,c=0;
	int x=n1/1;
	a+=x;
	
	int xx=n2/5;
	b+=xx;
	n2-=n2/5*5;
	int yy=n2/1;
	b+=yy;
	
	int xxx=n3/11;
	c+=xxx;
	n3-=n3/11*11;
	int yyy=n3/5;
	c+=yyy;
	n3-=n3/5*5;
	int zzz=n3/1;
	c+=zzz;
	
	cout<<min(a,min(b,c));
	return 0;
}