package Yukicoder

fun main(args: Array<String>) {
    fun readLineLongArray(): List<Long> {
        val str = readLine() as String
        val arrStr = str.split(" ")
        val ret = arrStr.map { it.toLong() }
        return ret
    }

    fun readLineLong(): Long {
        val str = readLine() as String
        return str.toLong()
    }

    fun readLineInt(): Int {
        val str = readLine() as String
        return str.toInt()
    }

    fun readLineIntArray() : List<Int> {
        val str = readLine() as String
        val arrStr = str.split(" ")
        val ret = arrStr.map { it.toInt() }
        return ret
    }

    fun readLineDoubleArray(): List<Double> {
        val str = readLine() as String
        val arrStr = str.split(" ")
        val ret = arrStr.map { it.toDouble() }
        return ret
    }

    fun readLineDouble() : Double {
        val str = readLine() as String
        return str.toDouble()
    }


//    fun readLineStringArray(): List<String> {
//        val str = readLine() as String
//        val arrStr = str.split(" ")
//        return arrStr
//    }

    val input = (readLine() as String).split(" ")
    val w = input[0].toInt()
    val h = input[1] .toInt()
    val c = input[2].toCharArray()[0]
    val solt = if (c == 'B') 0 else 1
    for (i in 1..h) {
        for (j in 1..w) {
            if ((i+j+solt)%2 == 0) {
                print("B")
            } else {
                print("W")
            }
        }
        println()
    }
}