https://soooprmx.com/objective-c-%ed%95%9c%ea%b8%80%ec%9d%98-%ec%b4%88%ec%84%b1-%ec%a4%91%ec%84%b1-%ec%a2%85%ec%84%b1-%eb%b6%84%eb%a6%ac%ed%95%98%ea%b8%b0/
Objective-C 한글의 초성을 분리하기