count = 1
for i in urls:
   if count <= 9:
       os.system("/usr/local/bin/youtube-dl -o 'Track_0" + str(count) + "_-_%(title)s.%(ext)s' --restrict-filenames " + i)
   else:
       os.system("/usr/local/bin/youtube-dl -o 'Track_" + str(count) + "_-_%(title)s.%(ext)s' --restrict-filenames " + i)
   count = count + 1