#include<bits/stdc++.h>
using namespace std;
#define int long long
signed main(){
	ios::sync_with_stdio(0);
	cin.tie(0);
	cout.tie(0);
	int n;
	cin>>n;
	int minn=n;
	if(n%5==0){
		minn=min(minn,n/5);
	}
	if(n%11==0){
		minn=min(minn,n/11);
	}
	if(n%11%5==0){
		minn=min(minn,n/11+n%11/5);
	}
	minn=min(minn,n/5+n%5);
	minn=min(minn,n/11+n%11);
	minn=min(minn,n/11+n%11/5+n%11%5);
	cout<<minn;
	return 0;
	
}