Bud gets a budget $2-$round DES system. It uses a $32$ bit $L,$ a $32$ bit $R,$ and a $32$ bit $K.$ The function is$,f(R,K)=Ro+K,$ with the same key for each round. Moreover, to avoid transmission errors, he always uses a $32$ bit message $M$ and lets $L_0=R_0=M.$ Eve does not know Bud's key but she obtains one of Bud's encryption. Describe how Eve can obtain the plaintext $M$ and the key $K.$