Combining 2 lists into a tree [answered]

Hi,

I’m using GH again but it’s been a while…
can someone point me in the right direction to combine 2 lists into a tree with items pairing the 2 lists:

listA    listB
  A       k
  B       l
  C      m

New tree:
  Ak
  Bl
  Cm

Thanks
-Willem

I got an answer on the GH forum:

Thanks ALEX