#include<bits/stdc++.h>
using namespace std;
struct water{
	int num,t;
}pp[10000000];
bool cmp(water a,water b){
	return a.t<b.t;
}
int main(){
	int n,y,i,j;
	int time;
	double ttt;
	scanf("%d",&n);
	for( i=1;i<=n;i++){
		scanf("%d",&pp[i].t);
		pp[i].num=i;
	}
	sort(pp+1,pp+n+1,cmp);
	for( i=1;i<=n;i++){
		printf("%d ",pp[i].num);
	}
	printf("\n");
	for(j=n-1;j>=1;j--){
		 y=n-j;
		time+=pp[y].t*j;
	}
	ttt=time*1.00/n;
	printf("%.2lf",ttt);
	return 0;
}