Aspect Ratio Calculation for NMOS and PMOS in Telescopic Single-Ended OTA (3.3V Supply)

Hi,

How do I determine the aspect ratios of all the NMOS and PMOS of a telescopic single ended OTA through analytical techniques?

Because, I have tried trial and error method in order to improve on my Adc gain but not yielding and also my output common mode is not at virtual ground for a 3.3-V supply.

Thanks!