  The following special case of a conjecture by Loehr and Warrington was proved
recently by Ekhad, Vatter, and Zeilberger:
  There are 10^n zero-sum words of length 5n in the alphabet {+3,-2} such that
no zero-sum consecutive subword that starts with +3 may be followed immediately
by -2.
  We give a simple bijective proof of the conjecture in its original and more
general setting. To do this we reformulate the problem in terms of cylindrical
lattice paths.
