๋ง ๊ทธ๋Œ€๋กœ 12m~18m ๋‚ด์˜ ๋ฒ”์œ„์—์„  ์Šฌ๋Ÿฌ๊ทธํƒ„์ด ํž™ํŒŒ์ด์–ด ์Šคํ”„๋ ˆ๋“œ ๋‚ด์— ์žˆ๋Š” ์ ์„ '์•Œ์•„์„œ ์ซ“์•„๊ฐ€์„œ' ๋ช…์ค‘์‹œํ‚ด