import java.io.PrintWriter

fun main(args: Array<String>) {
  val pw = PrintWriter(System.out)
  val (H, W, A, B) = readLine()!!.split(" ").map{ it.toInt() };
  for (i in 0 until H) {
    for (j in 0 until W)
      pw.print(if ((i < B).xor(j < A)) 1 else 0);
    pw.println();
  }
  pw.close();
}