H, W, A, B = gets.split.map(&:to_i)

(H - B).times do
  arr = []
  (W - A).times do
    arr << 0
  end
  A.times do
    arr << 1
  end
  puts arr.join("")
end

(B).times do
  arr = []
  (W - A).times do
    arr << 1
  end
  A.times do
    arr << 0
  end
  puts arr.join("")
end