#include <iostream>
#include <utility>
#include <iomanip>
#include <set>
using namespace std;

struct cmp{
	bool operator()(const pair<int, int>& a, const pair<int, int>& b) const{
		if(a.second != b.second) return a.second < b.second;
		else return a.first < b.first;
	}
};
int main(){
	set<pair<int, int>, cmp> s;
	int n;
	cin >> n;
	int tmp;
	double all = 0;
	for(int i = 0; i < n; i++){
		cin >> tmp;
		s.emplace(make_pair(i + 1, tmp));
	} 
	auto x = s.begin();
	for(int i = 0; i < n; i++){
		cout << (*x).first << " ";
		all += (n - i - 1) * (*x).second; 
		x++;
	}
	cout << endl;
	cout << fixed << setprecision(2) << all / n << endl;
	return 0;
}