In the last page the symbol on the bottom left pod looked like six, and the one on the left in the middle looked like 5 but it was kind of obscure. The one that the Pein we saw go into the cave got into seems to be the one that was on the bottom right on the last page, but I don't recognize that symbol.

My theory is that he's got numbered beds for all the bodies he can switch to at will, I wonder if they are in fact different from one another or if they're just clones he uses to conserve strength or something.