$(1$ point$)$ Alice and Bob are using the ElGamal cipher with the parameters $p=193$ and $=5.$

Alice makes the mistake of using the same ephemeral key for two plaintexts, $x_1$ and $x_2.$ The eavesdropper

Eve suspects that $x_1=146.$ She sees the two ciphertexts $y_1=141$ and $y_2=167$ in transit; these are the

encryptions of $x_1$ and $x_2,$ respectively.

a$)$ What is the masking key $k_M?$

b$)$ What is the plaintext $x_2?$