#include<bits/stdc++.h>
using namespace std;
const int maxn=2e5+9;
int n;
int dp[maxn];
int main(){
//freopen(".in","r",stdin);
//freopen(".out","w",stdout);
cin>>n;
memset(dp,0x3f,sizeof(dp));
dp[0]=0;
for(int i=1;i<=n;i++){
if(i>=1) dp[i]=min(dp[i],dp[i-1]+1);
if(i>=5) dp[i]=min(dp[i],dp[i-5]+1);
if(i>=11) dp[i]=min(dp[i],dp[i-11]+1);
}
cout<<dp[n];
}斜体文本