h, w, a, b = gets.split.map(&:to_i)

ans = Array.new(h) { Array.new(w) }
for i in 0..h-1
    for j in 0..w-1
        ans[i][j] = (i <= b ? 1 : 0) ^ (j <= a ? 1 : 0)
    end
end
puts ans.map(&:join).join("\n")