let computeMin xs =
    let ys = Set.ofSeq xs |> Set.toSeq
    if Seq.length ys < 2 then 0
    else Seq.pairwise ys |> Seq.map (fun (x, y) -> y - x |> abs) |> Seq.min

let () =
    let _ = stdin.ReadLine()
    let xs = stdin.ReadLine().Split(' ') |> Array.map int
    computeMin xs |> printfn "%d"