Neck and shoulder shaping

by Jane
(Canada)

I am knitting a sweater front ... 143 stitches in total. The neck and shoulder shaping begins with an instruction to pattern 39 stitches across, turn, reserving remaining stitches on a holder. Neck edge decreases and casting off gives the shoulder and neck shaping for the first side of the sweater. Then the pattern tells me to put Centre 27 stitches on a holder for neckband, join yarn and pattern to the end and begin reversing shaping. I assume the shaping for the second shoulder will happen on 39 stitches and 27 stitches are on hold for neck band but that leaves 38 stitches, 19 on each side of the centre stitches. Not sure if I am misreading or misunderstanding the pattern but I am not sure what to do with these extras. Hope this makes sense. Thanks for your help.