Show that the following languages $$have infinite index with respect to the Myhill$-$Nerode relation.

Note: Not all equivalence classes need to be specified.

a$)$ L $=\{(1$n$0$n$)$k$|$ n$,$ k in N$\}$

b$)$ The language L which contains all words over the alphabet $\backslash$Sigma $=\{0,1\}$ that have odd length

and a $1$ in the middle.