import java.util.*

fun main(args: Array<String>) {
    val (h,w,a,b ) = readLine()!!.split(" ").map { it.toInt() }
    var s1=""
    var s2=""
    for(j in 0 until w){
        if(j<a){
            s1+="0"
            s2+="1"
        }
        else{
            s1+="1"
            s2+="0"
        }
    }
    for(i in 0 until h){
        if(i<b)println(s1)
        else println(s2)
    }
}

