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

up_array = Array.new(A, 0).concat(Array.new(W-A, 1)).join("")
down_array = Array.new(A, 1).concat(Array.new(W-A, 0)).join("")
B.times { puts up_array }
(H-B).times { puts down_array }
