import java.util.*

fun main(args: Array<String>) {
    val tokenizer = StringTokenizer(readLine()!!)
    val h = tokenizer.nextToken().toInt()
    val w = tokenizer.nextToken().toInt()
    val a = tokenizer.nextToken().toInt()
    val b = tokenizer.nextToken().toInt()
    for (y in 0 until h) {
        println(String(CharArray(w) { x -> if (y < b == x < a) '1' else '0' }))
    }
}