Write a pseudocode to evaluate and print the following expressions. Do not use a programming languaje $($e$.$g$.,$ MATLAB or Python$)$ to write the pseudocode. Ask the user for input$($s$)$ if needed.

$1$a$.$

$S_1={\displaystyle \underset{i=1}{\overset{20}{}}}\frac{(3+5i{)}^4}{2i}$

$1$ b$.$

$S_2=\frac{cos(2x)-2x}{5(y-1)}$

Note: Specify the condition under which you cannot calculate $S_2$ as a conditional statement within your cod Notify the user to provide other inputs if they are not adequate for the calculation of $S_2.$