Drop the high point shoulder by 1cm and from this point measure 15,5cm.
This will be the shoulder line.
Then, add 5cm that will be tucked in underneath the shoulder pad.
Drop 25cm for the armhole and find the 1/4 of bust circumference as 26cm (size S/M).
Finish drawing the bodice as a rectangular piece where the 1/4 of the waist measures 25cm.
Front and back pattern are exactly the same, we only changed the neckline dropping it 5cm more on center front.