What is the easiest way to recognize captcha?

Question

CAPTCHA

Friends, hello everyone.
There is one local web service whose service is protected by captcha.
There are no API options at the moment and it is not known if they will be at all - there are no reliable ones for this.
The captcha looks rather primitive and that's why we came up with the idea to try to automate its recognition.
A couple of examples of captcha:
1)
2)
3)
Please tell me if this is possible?
What is the easiest way to recognize such a captcha with an acceptable level of accuracy? Maybe there are already proven methods, how to do it faster and easier?
PS I know that this is a problem of computer vision, machine learning (convolutional neural networks, etc.), it just seems that at this stage it is an overkill in a sense, but I can, of course, be wrong.
Thanks a lot to everyone.

Answer 1

If you "go" and not "checkers", then CapMonster
Supports many captchas "out of the box" + there is an opportunity to teach new captchas on your own.

Answer 2

Simple captcha.
antigate.com or write your own recognizer should not be a problem.