#include<bits/stdc++.h> using namespace std; int main(){ int a[100],b; double high,n,num; cin>>n; for(int i=1;i<=n;i++){ cin>>high; num=num+high; a[i]=high; } printf("%.1lf",num/n); cout<<endl; for(int j=1;j<=n;j++){ if(a[j]>num/n){ cout<<j<<':'<<a[j]<<' '; } } return 0; }