import java.util.*

fun main(args: Array<String>) {
    val scanner = Scanner(System.`in`)
    val h = scanner.nextInt()
    val w = scanner.nextInt()
    val a = scanner.nextInt()
    val b = scanner.nextInt()
    var str = ""
    var str2 = ""
    //var countW = IntArray(h)
    //var countH = IntArray(w)
    val array = Array(h, {Array(w, {0})})
    for(j in 0..w-1) {
        if(j < a) {
            str+="0"
            str2+="1"
        }
        else {
            str+="1"
            str2+="0"
        }
    }
    for(i in 0..h-1){
        if(i < b) println(str)
        else println(str2)
    }
}