The spelling of "McKie" may seem confusing, but it is actually quite straightforward when you break it down using IPA phonetic transcription. The first sound is "m," which is pronounced as /m/. The second sound is a voiced velar stop, represented in IPA as /k/. The third sound is a long "e," pronounced as /i:/, and the final sound is a silent "e." Therefore, the correct spelling of this word is "McKie," with a total of four letters.