
function reverse(a){
  return a === 0 ? 1 : 0;
}

function Main(input) {
  const tmp = input.split("\n")[0].split(" ").map((v) => (parseInt(v)));
  console.log(tmp);
  const h = tmp[0];
  const w = tmp[1];
  const a = tmp[2];
  const b = tmp[3];

  const ans = [...Array(h).keys()].map((v) => v < b ? 0 : 1).map((v) => {
    return [...Array(w).keys()].map((x) => x < a ? v : reverse(v))
  })

  console.log(ans.map((v) => v.join("")).join("\n") + "\n");
}

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