open System
open System.Collections.Generic

module InputUtility =
    let InputTokens = new Queue<string>()

    let EnsureInput () =
        if InputTokens.Count = 0 then
            let input = Console.ReadLine ()
            let s = input.Split ([|' '|], StringSplitOptions.RemoveEmptyEntries)
            if s.Length > 0 then
                for x in s do InputTokens.Enqueue(x)
                true
            else false
        else true

    let rec ReadNext () =
        if EnsureInput () then InputTokens.Dequeue ()
        else ReadNext ()

    let ReadNextInt () = ReadNext () |> int

    let Read2Int () = ReadNextInt (), ReadNextInt ()

    let Read3Int () = ReadNextInt (), ReadNextInt (), ReadNextInt ()

    let ReadListOf f n =
        let rec loop acc = function
            | 0 -> List.rev acc
            | c -> loop ((ReadNext () |> f) :: acc) (c-1)
        loop [] n

    let MultipleCaseWithId f =
        let caseNum = ReadNextInt ()
        let rec loop index =
            if index = caseNum then ()
            else
                f index
                loop (index + 1)
        loop 0

    let MultipleCase f = MultipleCaseWithId (fun _ -> f ())

    let ReadList n =
        let rec loop acc = function
            | 0 -> List.rev acc
            | c -> loop (ReadNext () :: acc) (c-1)
        loop [] n

open InputUtility

module _2017QualA =
    let private toBoolStr b = if b then "Yes" else "No"

    let private allPairs s1 s2 = seq { for a in s1 do for b in s2 do yield (a, b) }

    let private FourColoring () =
        let n, m, d = Read3Int ()
        let temp = "RYGB"
        let u = temp.Length
        let arr = Array2D.zeroCreate n m
        if d % 2 = 0 then
            let hd = d / 2
            for (x, y) in allPairs [0..n-1] [0..m-1] do
                let a, rb = x / hd, y / hd
                let b = if a % 2 = 1 then rb + 2 * u - 1 else rb
                let c = (u - a / 2 % u + b / 2) % u
                let e = if a % 2 = 1 then 2 else 0
                arr.[x, y] <- (c + e) % u
        else
            for (x, y) in allPairs [0..n-1] [0..m-1] do
                arr.[x, y] <- (x + y) / d % u
        for x in [0..n-1] do
            for y in [0..m-1] do
                printf "%c" temp.[arr.[x, y]]
                //printf "%d" arr.[x, y]
            printfn ""

    let Entry = FourColoring

_2017QualA.Entry ()