#include<bits/stdc++.h>
using namespace std;
int main(){
	int n;
	cin>>n;
	int cnt_11;
	int cnt_5;
	int cnt_1;
	if(n<5){
		cout<<n;
	} 
	else if(n>=5&&n<11){
		if(n%5==0) {
			cout<<n/5;
			return 0;
		}
		cnt_5=n/5;
		n=n-cnt_5*5;
		cnt_1=n;
	} 
	else {
		if(n%11==0){
			cout<<n/11;
			return 0;
		} 
		else if(n%5==0){
			cout<<n/5;
			return 0;
		} 
		
		cnt_11=n/11;
		n=n-cnt_11*11;
		cnt_5=n/5;
		n=n-cnt_5*5;
		cnt_1=n;
	}
	int c=0;
	c=cnt_11+cnt_5+cnt_1;
	cout<<c;
	 
	return 0;
}