#include<bits/stdc++.h>
using namespace std;
int n,a[60]={0,1,2,3,4,1,2,3,4,5,2,1,2,3,4,3};
int main()
{
    cin>>n;
    for(int i=16;i<=54;i++)a[i]=min(a[i-1]+1,min(a[i-5]+1,a[i-11]+1));
    cout<<n/55*5+a[n-n/55*55];
    return 0;
}

90pts,QWQ