Highest peak name and elevation by country

with
    PeaksInfo_CTE(Country, Mountain, Peak, Elevation)
    as
        (select
            [C].CountryName,
            [M].MountainRange,
            [P].PeakName,
            [P].Elevation
        from
            Countries as [C]
        left join
            MountainsCountries as [MC]
        on
            [C].CountryCode = [MC].CountryCode
        left join
            Mountains as [M]
        on
            [MC].MountainId = [M].Id
        left join
            Peaks as [P]
        on
            [M].Id = [P].MountainId),
    HighestPeakInfo_CTE(Country, Elevation)
    as
        (select
            Country,
            max(Elevation)
        from
            PeaksInfo_CTE
        group by
            Country)
select top 5
    [A].Country,
    case
        when [A].Peak is null
            then '(no highest peak)'
        else [A].Peak
    end as [Highest peak name],
    case
        when [A].Elevation is null
            then 0
        else [A].Elevation
    end as [Elevation],
    case
        when [A].Mountain is null
            then '(no mountain)'
        else [A].Mountain
    end as [Mountain name]
from
    PeaksInfo_CTE as [A]
left join
    HighestPeakInfo_CTE as [B]
on
    [A].Country = [B].Country
where
    [A].Mountain is null
    and [A].Peak is null
    and [A].Elevation is null
    or [A].Elevation = [B].Elevation
order by
    [A].Country asc,
    [A].Peak asc