Five-page handoff: the right count can conceal the wrong order

main-two.pdf contains A1 and A2; appendix-three.pdf contains B1, B2 and B3. The fictional requirement is main document followed by appendix: A1 → A2 → B1 → B2 → B3.

1. Select only these two PDFs in Merge PDFs, not the outer exercise ZIP. Move the main document before the appendix in the input list.

2. Process, save merged.pdf and reopen it. Record every marker, especially the boundary from A2 on page 2 to B1 on page 3.

3. Make a second merge with reversed input order. Save it as wrong-order.pdf without overwriting either source.

Accept five pages in the exact order A1, A2, B1, B2, B3. The equation 2+3=5 checks quantity; the handoff record must also identify source boundaries.

The reversed output also has five pages, but starts with B1. Reject it, restore the file order and regenerate. A successful download does not establish the required reading order.
