"Z, Y, X," you say, immediately finding yourself on uncertain ground.
"I mean, sure, go ahead," Manish mumbles.
"W, V…" You can see why Manish said it was so hard.
Manish takes pity on you after another few letters. "Stop!"
"34, 55, 89," you say, launching into the Fibonacci sequence. You practiced enough that you remember the next two numbers, too. "144, 233." After that you have to do addition in your head. You get to 987 before you slow down enough to stop.
Manish doesn't comment on your success. Instead, he says, "You remember what letter you stopped on?"