open System

let ri () = stdin.ReadLine() |> int
let ria () = stdin.ReadLine().Split() |> Array.map int

type Sol() =
    member this.Solve() = 
        let [|a;b|] = stdin.ReadLine().Split() |> Array.map double |> Array.sort
        let x = b*b - a*a |> sqrt 
        let z = a*a + b*b |> sqrt
        (if a = b then z else x ) |> printfn "%f"
        
let mySol = new Sol()
mySol.Solve()