#include<bits/stdc++.h>
using namespace std;
int a[1001],b[1001],z[1001],n;
double s;
int main()
{
	cin>>n;
	for(int i=1;i<=n;i++)
	{
		cin>>a[i];
		b[i]=a[i];
	}
	sort(a+1,a+n+1);
	for(int i=1;i<=n;i++)
	{
		s+=a[i]*(n-i);
		for(int j=1;j<=n;j++)
		{
			if(z[i]==1) continue;
			if(b[j]==a[i])
			{
				cout<<j<<" ";
				z[j]=1;
				break;
			}
		}
	}
	cout<<endl;
	cout<<fixed<<setprecision(2)<<s/n; 
	return 0;
}