pr -l 63 dice_of_doom_v1.ex   >dice_of_doom_v1.pr
pr -l 63 dice_of_doom_v1a.ex  >dice_of_doom_v1a.pr
pr -l 63 dice_of_doom_v1b.ex  >dice_of_doom_v1b.pr
pr -l 63 dice_of_doom_v2.ex   >dice_of_doom_v2.pr
pr -l 63 dice_of_doom_v2a.ex  >dice_of_doom_v2a.pr
# pr -l 63 dice_of_doom_v2b.ex  >dice_of_doom_v2b.pr
chmod 644 *.ex *.pr