#include <iostream>
#include <algorithm>
#include <cstdio>
using namespace std;
struct student{
    int num, x;
} t[1005];
bool cmp(student a, student b){
    if (a.num != b.num) return (a.num < b.num);
    else return (a.x < b.x);
}
int main () {
    int n, sum = 0;
    scanf("%d", &n);
    for (int i = 1; i <= n; i++){
        scanf("%d", &t[i].num);
        t[i].x = i;
    }
    sort(t + 1, t + n + 1, cmp);
    for (int i = 1; i <= n; i++){
        printf("%d ", t[i].x);
        sum += t[i].num * (n - i);
    }
    cout << endl;
    printf("%.2f", 1.0 * sum / n);
    return 0;
}
谢谢帮看的朋友！！