https://gfycat.com/BlaringFastLeafcutterant
난간 없을때
https://gfycat.com/TenseDefiniteAmericanrobin
https://gfycat.com/UnselfishDarlingCopepod
난간 없을때
https://gfycat.com/TenseDefiniteAmericanrobin
난간 있을때
https://gfycat.com/UnselfishDarlingCopepod
계산착오
ㅠㅠㅠㅠㅠㅠㅠㅠㅠㅠㅠㅠㅠㅠㅠㅠㅠㅠㅠㅠㅠㅠㅠㅠㅠㅠㅠㅠㅠㅠㅠ