Five

Misty blinked, looking herself directly in the eyes.

"Did I drown?"
"Did I drown?"

Two of them spoke at the same time, while the other three screamed.

Their screaming made the first two scream.

Soon enough everyone was screaming. Rather loudly.

"CAN YOU QUIET DOWN!" A red haired lady in a business suit slammed the gym door open. "YOU DON'T REALIZE HOW LATE IT IS!"

"Lorelei?"

"Misty?"

"So, when you woke up there were suddenly five of you?" Lorelei sighed. "I wouldn't believe a word of it if I wasn't seeing it.""I mean I thought I was looking at intruders," one Misty said, two others nodding with her. "I didn't realize they were identical to me until you came."

"I just thought I was delusional," another said.

"But what can we do about this?" Lorelei sighed. "I've seen gyms with two gym leaders, and even a gym with three, but I've never seen a gym with five gym leaders."

"Well as the original," Misty began. "I can just-"

"Hold on," Misty interrupted. "Who died and deemed you the original?"

"Yeah," Misty said. "I'm the original!"

"No, I am!"

"I am!"

And thus started an argument that made Lorelei's head spin.

But this was a real pickle. If Misty couldn't even distinguish between herselves then how could anyone determine original from fake.
And that was when Lorelei had an idea.