The guy thinks for a minute, and finally gives his final answer: 0.
The host (I dunno her name) promptly tells him the one multisyllable letter he overlooked: W. He loses! And I'm standing there thinking, HOW HARD IS IT TO JUST RECITE THE ALPHABET? That's what I did while watching! It wouldn't even have counted as cheating to recite it out loud!
To quote that Asian guy from "UHF", YOU SO STUPIIIIID!