object Main {
  def main(args: Array[String]) = {
    val sc = new java.util.Scanner(System.in)
    val h, w, a, b = sc.nextInt
    sc.close()

    (0 until h).foreach(hh => {
      if (hh < h - b) println("0" * a + "1" * (w - a))
      else println("1" * a + "0" * (w - a))
    })
  }
}