let rsa () = stdin.ReadLine().Split(' ')
let ria () = rsa () |> Array.map (fun x -> int x)

let [| A; B |] = ria()

let answer x y =
  let add = x + y
  let mul = x * y
  let sub = x - y
  if add >= mul && add >= sub then add
  elif mul >= add && mul >= sub then mul
  else sub
  

let _ans = answer A B
printfn "%d" _ans