How to do the following or type it in R studio. Thanks in advance!

$1)$ Write an R script to practice the $$if$-$else$$ command, for two

alternatives. For alternative $1$ compute the sum of $1,3,$ and $5.$ For

alternative $2$ compute the product of $2$ and $4.$ Define the alternative

by choosing the value of variable X at the beginning of the code,

and check X by using $$if$$ to decide which alternative to compute.

$2)$ Write an R script to practice the $$while$$ command. Use a $$while$$

loop, which prints the elements of the sequence $2,4,6,...,20.$ Use

the start value $2,$ and increment the index by $2$ in the loop.