Then that is your starting point.
Start with 20 today. No matter how many sets it takes do 20.
Tomorrow, add 5, and do the 25. The next day, add 5 more, so you do 30. Keep adding 5 per day and do them everyday.
You will find the number you can do with each set will increase over time. In 45 days, you will see a huge difference.
Fitness advice from @taskmaster4450le. Now I have seen it all, the man is a living dictionary 🤩
That one isnt book theory. It comes from practice.