let readString() = stdin.ReadLine()
let readStringArray() = stdin.ReadLine().Split(' ');
let readInt() = readString() |> int
let readIntArray() = readStringArray() |> Array.map (fun x -> int x)

let a, b = readIntArray() |> fun x -> (x.[0], x.[1])

match (a, b) with 
| (a, _) when a % 3 = 0 -> "Possible"
| (_, b) when b % 3 = 0 -> "Possible"
| (a, b) when (a + b) % 3 = 0 -> "Possible"
| _ -> "Impossible"
|> printfn "%s"