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
        b*b - a*a |> sqrt |> printfn "%.8f"
        
        
        ()
let mySol = new Sol()
mySol.Solve()