with c1 as (
	select hacker_id, count(*) as cc_ch
	from Challenges as c
	group by hacker_id
), c2 as (
	select max(cc_ch) as max_cc_ch 
	from c1
), c3 as (
	select cc_ch
	from c1
	where cc_ch < (select top 1 max_cc_ch from c2)
	group by cc_ch
	having count(*) = 1
	
	union 
	select max_cc_ch from c2
)
select h.hacker_id, h.name, c1.cc_ch
from c1 
join c3 on c1.cc_ch = c3.cc_ch
join Hackers as h on c1.hacker_id = h.hacker_id 
order by c1.cc_ch desc, hacker_id