The other day upon the stair,
I met a man who wasn't there.
He wasn't there again today,
I think he's from the CIA.

The following nest of begin and ends should be indented in a nest.

begin0
   begin1
      begin2
         begin3
            begin4
               begin wayout----------V
                                     It's scary out here
                                     So far from the left margin.
               end   wayout----------^
            end4
         end3
      end2
   end1
end0