あなたか私のどちらかが

either you or I

→ 貴方
phrase Rare #37,847
either you or I Used to indicate that one of two people—here, you or the speaker—is the subject of the sentence. The pattern XかYのどちらかが means “either X or Y.”
JA: あなたか私のどちらかが彼に電話しなければならない。
EN: Either you or I have to call him.