open System

[<EntryPoint>]
let main _ =
  let [|a; b|] = Console.ReadLine().Split(' ') |> Array.map int

  let ub = 2000000000
  let result =
      if a < b then
        let mid_large_small = a - 1
        let small_large_mid = b - a - 1

        mid_large_small + small_large_mid
      else
        let mid_small_large = (ub + 1) - a - 1
        let large_small_mid = a - b - 1

        mid_small_large + large_small_mid

  printfn "%d" result

  //exit code
  0