function Main(input) {
    const Param = input.split('\n')[0].split(' ')
    const H = i(Param[0])
    const W = i(Param[1])
    const d = i(Param[2])
    const matrix = init(H, W)
    for (var index_r = 0; index_r < H; index_r++) {
        for (var index_c = 0; index_c < W; index_c++) {
            var entry = matrix[index_r][index_c]
            if(index_r + d < H && entry == matrix[index_r + d][index_c]){
                matrix[index_r + d][index_c]++
                if(matrix[index_r + d][index_c] == 3) matrix[index_r + d][index_c] = 0
            }
            if(index_c + d < W && entry == matrix[index_r][index_c + d]){
                matrix[index_r][index_c + d]++
                if(matrix[index_r][index_c + d] == 3) matrix[index_r][index_c + d] = 0
            }
            if(index_r + d < H && index_c + d < W && entry == matrix[index_r + d][index_c + d]){
                matrix[index_r + d][index_c + d]++
                if(matrix[index_r + d][index_c + d] == 3) matrix[index_r + d][index_c + d] = 0
            }
        }
    }
    const str = matrix.map(function(row){
        return row.join('')
    }).join('\n').replace(/0/g,'R').replace(/1/g,'Y').replace(/2/g,'G').replace(/3/g,'B')
    console.log(str)
}
function init(H, W){
    const matrix = []
    for (var index_r = 0; index_r < H; index_r++) {
        matrix[index_r] = []
        for (var index_c = 0; index_c < W; index_c++) {
            matrix[index_r][index_c] = 0
        }
    }
    return matrix
}
function i(x){ return parseInt(x, 10)}
Main(require("fs").readFileSync("/dev/stdin", "utf8"));