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