#include <bits/stdc++.h>
using namespace std;
int n;
double ans;
struct pd {
    int t,n1;
}a[10001],p[10001];
bool cmp(pd a,pd b) {
	if(a.t!=b.t)
    return a.t<b.t;
    else return a.n1>b.n1;
}
main() {
    cin>>n;
    for(int i=1;i<=n;i++) {
        cin>>a[i].t;
        a[i].n1=i;
    }
    sort(a+1,a+n+1,cmp);
    for(int i=1;i<=n;i++) {
        cout<<a[i].n1<<" ";
    }
    cout<<endl;
    for(int i=1;i<=n;i++) {
     ans+=i*a[n-i].t;
    }
    printf("%.2lf",(double)ans/n);
    return 0;
}

91 分，求调