local h, w = io.read("*n", "*n")
local a, b = io.read("*n", "*n")
for i = 1, b do
  for j = 1, a do
    io.write(0)
  end
  for j = a + 1, w do
    io.write(1)
  end
  io.write("\n")
end
for i = b + 1, h do
  for j = 1, a do
    io.write(1)
  end
  for j = a + 1, w do
    io.write(0)
  end
  io.write("\n")
end
