#include <iostream>
#include <algorithm>
#include<iomanip>
using namespace std; 
struct node{
	int id;
	int t;
}a[100005];
int n;
double sum = 0;
bool cmp(node a,node b)
{
  	if(a.t == b.t) return a.id < b.id;
	return a.t < b.t;
}
int main()
{
	cin >> n;
	for(int i = 0; i < n; i++)
	{
		cin >> a[i].t;
		a[i].id = i + 1;
	}
	sort(a, a + n, cmp);
	for(int i=0;i<n;i++)
  	{
  	    cout<<a[i].id<<" ";
  	    sum+=a[i].t*(n-i-1);
  	}
	cout << endl;
	cout << fixed << setprecision(2) <<sum/n;
	return 0;
}