fun main(args: Array<String>) {
    agc038a()
}


fun agc038a() {
    val (h, w, a, b) = readLine()!!.split(" ").map { it.toInt() }

    val answer = (1..h).map { currH ->
        (1..w).map { it <= w - a }.joinToString(separator = "") { if (it == currH <= h - b) "0" else "1" }
    }

    println(answer.joinToString(separator = System.lineSeparator()))
}
