open System

let X,Y = 
    let t = Console.ReadLine().Split()
            |> Array.map(int)
    t.[0],t.[1]

match X,Y with
| _ when X = Y -> 0
| 0,_          -> 2
| _,0          -> 1
| _ when X = -Y -> 3
| _            -> -1
|> printfn "%i"