#include<bits/stdc++.h>
using namespace std; 
const int N=1e5+10;
    int i,n,sum;
    struct shui{
    	int id;
    	int su;
	}a[N];
	double ans;
int cmp(shui a,shui b){
	if(a.su==b.su)
	    return a.id<b.id;
	return a.su<b.su;
}
int main(){
	cin>>n;
    for(int i=1;i<=n;i++){
    	cin>>a[i].su;
    	a[i].id=i;
	}
	sort(a+1,a+n+1,cmp);
	for(int i=1;i<=n;i++){
		cout<<a[i].id<<" ";
		ans+=a[i].su+a[i].su*(n-i-1);
	}
    cout<<endl<<fixed<<setprecision(2)<<ans/n;
    return 0;
}