problem

<aside> πŸ’‘

개방-폐쇄 원칙(Open-Cloded Principle) -"ν™•μž₯ν•  λ•Œ κΈ°μ‘΄ μ½”λ“œλ₯Ό μˆ˜μ •ν•˜λ©° ν™•μž₯되면 μ•ˆλΌ!"

</aside>

resolve