Oh, okay. 26, not 24. I don't think it would have made a difference because on Floor 25 I landed right next to whatever it was that killed me.
I finally got to spend some good time with the ring of stealth today. It's great when you get to the Trolls... and the Black Unicorns I bet! Unfortunately, I met up with a spawned Troll in a maze. Even more unfortunately, I tried to get away with just using a scroll of monster confusion on him. After confusing him I missed like four times in a row and with 20 HP left he took me down with one blow despite a 9 armor. Then again, I never seem to understand if armor class determines ability to dodge an attack or affects how much damage you take on a hit. My strategy would have been to back up and hammer him with projectiles, but I had none. I left a wand of polymorph, a wand of slow monster, and a scroll of scare monster on the table. My main problem was my cursed -2 long sword. After two enchantments it was simply a 0,0 long sword when I died. Still, I think the pieces were in place for me to take it to the Medusas or beyond and I failed.
Oh, and 3-4 treasure rooms in the first 12 floors helped. I found and identified three rings of protection, a ring of dexterity, a ring of stealth, a ring of see invisible, a ring of searching, a ring of increase damage, a wand of polymorph, a wand of magic missile, a wand of drain life, and a wand of slow monster.