fun main(args: Array<String>) {
    val (H, W, A, B) = readInputLine().split(" ").map { it.toInt() }
    
    for (i in 1..B) {
        println("0".repeat(A) + "1".repeat(W - A))
    }
    for (i in 1..H - B) {
        println("1".repeat(A) + "0".repeat(W - A))
    }
}

fun readInputLine(): String {
    return readLine()!!
}
