1 2 3 4 E E E E * - X t * v c * v * handedness 1 2 3 L handedness 1 3 4 R handedness 2 3 4 R sheetS 1 4 2 sheetD 3 1 length 1 E 5 100 length 2 E 5 100 length 3 E 5 100 length 4 E 5 100