#include<iostream>
#include<cstdio>
#include<cstring>
#include<algorithm>
using namespace std;
int n;
double ans;
struct nond{
    int t,id;
}v[1011];
int cmp(nond a,nond b){
    return a.t<b.t;
}
int main(){
    //freopen("lpp.txt","r",stdin);
    scanf("%d",&n);
    for(int i=1;i<=n;i++){
        scanf("%d",&v[i].t);
        v[i].id=i;
    }
    sort(v+1,v+1+n,cmp);
    for(int i=1;i<=n;i++){
        cout<<v[i].id<<" ";
        ans+=v[i].t*(n-i);
    }
    printf("\n%.2lf",ans*1.0/n*1.0);
}