#include<bits/stdc++.h>
#define ll long long
#define IO ios::sync_with_stdio(0);cin.tie(0);cout.tie(0);
using namespace std;
ll a[1000000],b[1000000];
ll n;
double ans=0;
int main()
{
IO
cin>>n;
for (int i=1;i<=n;i++)
{
cin>>a[i];
b[i]=a[i];
}
for (int i=1;i<=n;i++)
{
a[i]=a[i]*1000+i;
}
sort(a+1,a+n+1);
sort(b+1,b+n+1);
for (int i=1;i<=n;i++)
{
ans+=b[i]*(n-i);
}
for (int i=1;i<=n;i++)
{
if (i!=n){
cout<<(a[i]%1000)<<' ';
}
if (i==n)
{
cout<<(a[i]%1000)<<endl;
}
}
cout<<fixed<<setprecision(2)<<ans/n;
return 0;
}