REGION all
  COORDINATES
    0.d0 0.d0 0.d0
    100.d0 1.d0 1.d0
  /
END

REGION west
  FACE WEST
  COORDINATES
    0.d0 0.d0 0.d0
    0.d0 1.d0 1.d0
  /
END

REGION east
  FACE EAST
  COORDINATES
    100.d0 0.d0 0.d0
    100.d0 1.d0 1.d0
  /
END
