H,W,A,B=$<.read.split.map(&:to_i)
# H,W,A,B=[7,4,2,3]

arr = Array.new(H) { Array.new(W,0) }

s = [0] * A + [1] * (W-A)
t = [1] * A + [0] * (W-A)

arr = [s] * B + [t] * (H-B)


puts arr.map {|l| l.join}