f = File.readlines("shading.txt")
$i = 0
$switch = 0

open('shading_out.txt','a'){|g|
while $i < f.size do
    if f[$i] == f[$i+1]
        g.puts ($switch).even?.to_s
    else
        if $i == (f.size-1)
            $switch-=1
            g.puts ($switch).even?.to_s
        else
            g.puts ($switch).even?.to_s
            $switch+=1
        end
    end
    $i += 1
end
}