open System

let ri () = stdin.ReadLine() |> int
let ria () = stdin.ReadLine().Split() |> Array.map int
let rec gcd a b = if a = 0L then b else gcd (b%a) a

type Sol() =
    member this.Solve() = 
        
        let [|N;D|] = ria() |> Array.map int64
        
        N / (gcd N D) - 1L |> printfn "%d"
        
        
        
        ()
let mySol = new Sol()
mySol.Solve()