let doIt () =
    let N = stdin.ReadLine () |> int
    let maxN = N * N
    let field = Array2D.zeroCreate<int> N N
    let dxy = [| (1, 0); (0, 1); (-1, 0); (0, -1) |]

    let canMove x y dir =
        let dx, dy = dxy.[dir]
        let nx, ny = x + dx, y + dy
        nx >=0 && nx < N && ny >= 0 && ny < N && field.[ny, nx] = 0
        
    let rec move x y n dir =
        if n > maxN then ()
        else
            field.[y, x] <- n
            let nextDir =
                if canMove x y dir
                then dir
                else (dir + 1) % 4
            let dx, dy = dxy.[nextDir]
            move (x + dx) (y + dy) (n + 1) nextDir

    move 0 0 1 0
    
    let formatLine y =
        seq {for x in 0..(N - 1) -> sprintf "%03d" field.[y, x]} |>
        Seq.reduce (fun s1 s2 -> s1 + " " + s2)

    seq {for y in 0..(N - 1) -> formatLine y} |> Seq.iter (printfn "%s")

doIt ()