7fe4f67fb3871b8723ed8396379c701f4cb404924602c5c17528e8863e063a614f6f3a0cbeb41106d953d719545285d2761495c012

0b9cf400b08768832399f293469c706bbefa36f6403117d00fd557d7ab37800bd40459509eb6f1db107936148a5a7de571a5fcc8f8

0f9e8070b5856ef423e78594309c701b2afd5db9dd7687bee56134bf759453741780a53c2ddb477f0f35dfbc1e457cb04b06c1e79e

걍 표면이 마찰에 의해 쓸린거다 vs 크랙이다