#include<iostream>
#include<cstdio>
#include<algorithm>
#define MAXN 100001
using namespace std;
int n,sumn=0;
struct Node{
	int id,t;
}t[MAXN];
bool cmp(Node a,Node b){
	return a.t<b.t;
}
int main(){
	cin>>n;
	for(int i=1;i<=n;i++) cin>>t[i].t,sumn+=t[i].t,t[i].id=i;
	sort(t+1,t+n,cmp);
	for(int i=1;i<=n;i++) cout<<t[i].id<<" ";
	printf("\n%.2lf",(double)sumn/n);
	return 0;
}

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