//#include<bits/stdc++.h>

 #include<set>

 #include<iostream>

 #include<cstdio>

 #include<stdlib.h>

 #include<cstring>

 #include<queue>

 #include<stack>

 #include<algorithm>

 using namespace std;

 int n;

 const int maxn = ;

 struct node{

     int id, t;

 }peo[maxn];

 bool cmp(node a, node b)

 {

     return a.t < b.t;

 }

 int main()

 {

     scanf("%d", &n);

     for(int i = ; i < n; i++){

         scanf("%d", &peo[i].t);

         peo[i].id = i + ;

     }

     sort(peo, peo + n, cmp);

     double ans = ;

     for(int i = ; i < n; i++){

         printf("%d ", peo[i].id);

         ans += 1.0 * peo[i].t * (n - i - );

     }

     //cout<<ans / n<<endl;

     printf("\n%.2f\n", ans / n);

     return ;

 }