/*
TASK:fsort
LANG:C++
*/
#include<iostream>
using namespace std;
int main()
{
 int a[1000],k,r,i,br1=0,br2=0,fl=0,p,t=1,n;
 cin>>n;   
 for(i=0;i<n;i++)
 {cin>>a[i];
 if(i!=0)
 {if(a[i]>=a[i-1])
  br1++;
  if(a[i]<=a[i-1])
  br2++;
 }}
 if(br1==n-1) 
  {fl=1;cout<<"-1";}
 if(br2==n-1)
 {fl=1;cout<<n;}
 if(fl==0)  
   for(i=n*t;i>2;i--)
 {  k=0;
    for(r=1;r<i;r++)
     {
      if(a[k]<=a[r])
      k=r;
     }
    for(p=0;p<=k/2;p++)
     a[p]=a[k-p];
    for (p=0;p<i/2;p++)
     a[p]=a[i-1-p];
  
    br1=0;br2=0;t=1; 
    for(p=1;p<i;p++)
     {if(a[p]>=a[p-1]) br1++;
     if(a[p]<=a[p-1]) br2++;}
    if(br1==i-1)
     t=0;
    if(br2==i-1)
     {
      t=0;          
     }
    if(k==0)
     if(br2!=i-1)cout<<i<<" ";
     else
         for (p=0;p<i/2;p++)
              a[p]=a[i-1-p];
    else
       if((i!=k+1)||(br2!=i-1)) 
        {cout<<k+1<<" ";
         if(br2!=i-1)cout<<i<<" ";        
        }
       else
           cout<<i<<" ";   
        
                             
 }
 if(a[1]>a[2])
 cout<<"2"<<" ";
  cout<<endl;
  system ("pause");
  return 0;
}
