#include "iostream.h"
void search(int a[],int low,int high,int c)
{
	int mid;
	mid=(low+high)/2;
	if(low<=high)
	{
		if(a[mid]>mid)
			search(a,low,mid-1,c);
		else if(a[mid]<mid)
			search(a,mid+1,high,c);
		else
		{
			c++;
			cout<<mid<<" ";
			search(a,low,mid-1,c);
			search(a,mid+1,high,c);
		}
	}
	else if(low>high&&!c)
		cout<<"none"<<endl;
}

void main()
{
	int n,m=1;
	int c=0;
	cin>>n;
	int *a=new int[n];
	for(int i=1;i<=n;i++)
		cin>>a[i];
	search(a,m,n,c);
}