https://purengom.com/2010/10/23/iphone-1%eb%85%84%ec%9d%84-%ec%95%9e%eb%91%90%ea%b3%a0-%ec%9a%b0%eb%a6%ac%ea%b0%80-%ec%a7%84%ec%a7%9c%eb%a1%9c-%eb%b0%94%eb%80%90%ea%b2%83%ec%9d%80/