Shinra Building level 63 door puzzle

[Erdrick Holmes]

I nticed how you can only open three doors on this floor. And bythe time you've opened three proper doors and climbed through the air vents you only end up with two coupons. I wanna know, how do you get the one in the middle?

[Lord Xehanort]

Head to the top of the room and open it. Move over to the left room and enter the door toward the top. Grab Coupon A and head through the vent to Coupon C. Head back through the vent and head right to the door next to the middle room. Open it, head in, grab Coupon B, then hop in the air vent and head to the computer terminal.

[Erdrick Holmes]

Thanks man. That helped alot.