A plaintext is encrypted by using trigraph transformation and ElGamal encryption algorithm The Rublic keys p$,$ a$,$ and $$ and the Rrivate kex a are given as follows: $p=24391,a=37,=4336,a=2215.$ The following ciphertext is obtained. Find the original plaintext.

$(21873,16560)(14799,812)(5055,11343)(23596,23010)(23358,6767)(6604,20637)$

$(3304,165)(18805,13373)(19986,20619)(14372,8681)(13735,3921)(1893,23356)$

$(3104,6956)(10875,6779)(10449,1656)(15510,907)(17392,2869)$