h, w, a, b = gets.split.map(&:to_i)
1.upto(h) do |i|
    1.upto(w) do |j|
        if i <= b then
            if j <= a then
                print '1'
            else
                print '0'
            end
        else
            if j <= a then
                print '0'
            else
                print '1'
            end
        end
    end
    print "\n"
end
