#include<iostream>
#include<iomanip>
#include<cstdio>
#include<cstring>
#include<cmath>
#include<algorithm>
#include<string>
#include<algorithm>
#define LL long long
using namespace std;
const int N=1e5+10;
const int Inf=0x3f3f3f3f;
int n;
double time1 = 1.00 * 0;
struct per {
	int t;
	int num;
}a[N];

bool cmp(per a, per b){
	if(a.t==b.t){
		return a.num<b.num;
	}
	return a.t < b.t;
}

int main(){
	int n;
	cin >> n;
	for(int i = 1; i <= n; i++) {
		cin >> a[i].t;
		a[i].num = i;
	}
	sort(a + 1, a + n + 1, cmp);
	int sum = n - 1;
	for(int i = 1; i <= n; i++) {
		time1 += 1.00 * a[i].t * sum;
		sum--;
		cout << a[i].num << ' ' ;
	}
	time1 /= 1.00 * n;
	cout << endl;
	printf("%.2lf", time1);
}