#include<bits/stdc++.h>
using namespace std;
int v[1010]={0,1,2,3,4,1,2,3,4,5,2};
int main(){
	int k; 
	cin>>k;
	for(int i=12;i<=k;i++){
		v[i]=min(v[i-1],min(v[i-5],v[i-11]))+1;
	}
	cout<<v[k];
	return 0;
}