Restaurant plates

Raju works in the cleaning department of a restaurant. He has a large stack of n plates, numbered from 1 to n; the topmost plate has number A1, the next plate is A2, and so on; the bottom plate has number An. All numbers are distinct. But some customers are very choosy about the plate they eat in, they want their order in a particular plate. Raju has a list of m distinct particular plates he