function myout(text){console.log(text);}//standard output
function Main(input) {
	//input = parseInt(input);
	//input = input.trim().split(" ");
	//input = input.trim().split("\n");
	input = input.trim().split(" ").map((a)=>Number(a));
	//input = input.trim().split("\n").map((a)=>Number(a));
  var H = input[0];
  var W = input[1];
  var A = input[2];
  var B = input[3];
  var output = [];
  for(var i = 0; i < H; i++){
    var tmp = "";
    for(var j = 0; j < W; j++){
      if((i < B && j < A) || (i >= B && j >= A)){
          tmp += "0";
         }else{
         tmp += "1";
         }
    }
    output.push(tmp);
  }
  myout(output.join("\n"));
}

Main(require("fs").readFileSync("/dev/stdin", "utf8").trim());
