1 2 3 4 5 6 E E E E E E * t X X X t * X X t X * t X t * t X * X * handedness 1 2 3 R handedness 2 3 4 R handedness 3 4 5 L handedness 4 5 6 R handedness 5 6 1 R handedness 6 1 2 L sheetS 1 2 3 4 5 6