open System

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

type Sol() =
    member this.Solve() = 
        
        let (N,D) = stdin.ReadLine().Split(' ') |> Array.map int |> (fun a -> (a.[0],a.[1]))
        
        N / (gcd N D) - 1 |> printfn "%d"
        
        
        
        ()
let mySol = new Sol()
mySol.Solve()