If you had a code$-$based encryption scheme with a $20,000-$bit codeword size $($and k is half that$),$ and you didn$$t use either the Niederreiter or the circulant matrix optimizations, then how big would a public key be$,$ and how big would a ciphertext be$?$

Now, what would those two numbers be if you introduced circulant matrices but not Niederreiter?

What would they be if you used both circulant matrices and the Niederreiter optimization?