please solve it with steps and explain how to find Pb and c1 I don't understand this example well

q=257;Eq(a,b)=E257(0,4)y2=x34;G(2,2)Pm=(112,26) Encryption/Decryption To encrypt Pm from A to B : A chooses a random positive Bob: Bob private key : nB=101 Bob pubic key: PB=nBG=101(2,2)=(197,167) integer k PB=(197,167) Cipher text is: Cm={kG,Pm+kP8} Alice To decrypt, B: Alice picks private: k=41 C1=kG=41(2,2)=(136,128) multiply first point by Bob kPB=41(197,167)=(68,84) private Key: kGnB Pm+kPB=(112,26)+(68,84)=(246,174) Subtract from second point: Cm=(C1,C2)={(136,128),(246,174)} ==Pm+kPBnB(kG)Pm+k(nBG)nB(kPm Cm=(C1,C2)={(136,128),(246,174)} Bob computes ===C2nBC1(246,174)101(136,128)(246,174)(68,84)(112,26)