#include <cstdio>
#include <iostream>
#include <cmath>
using namespace std;

typedef long long Int;

void solve(Int N)
{
	Int ans=0;
	if (N<=10)
	{
		switch (N)
		{
			case 5:ans=1;break;
			case 6:ans=6;break;
			case 7:ans=3;break;
			case 8:ans=4;break;
			case 9:ans=3;break;
			case 10:ans=2;break;
		}
	}
	else
	{
		ans=ceil(N/5.0);
		switch (N%5)
		{
			case 2:ans++;break;
			case 4:ans++;break;
		}
	}
	cout<<ans<<endl;
}

int main()
{
	freopen("xcoins.in","r",stdin);
	freopen("xcoins.out","w",stdout);
	Int N;
	cin>>N;
	solve(N);
	return 0;
}