. |\ | \ | \ OUT ~~|~~~\~~~~~~~~~ | \ IN | \ | _-` |_-` ` p1 q1 . |\ r3, q2, q3 | \ r3, r2, q2 r2| \r3 OUT ~~|~~~\~~~~~~~~~ | \ IN | \ p3 | _-` q3 |_-` p2 ` q2 p2 q1 . |\ r2, q3, q2 | \ r2, r3, q3 r3| \r2 OUT ~~|~~~\~~~~~~~~~ | \ IN | \ p1 | _-` q2 |_-` p3 ` q3 p3 q1 . |\ r2, q3, q2 | \ r2, r3, q3 r3| \r2 OUT ~~|~~~\~~~~~~~~~ | \ IN | \ p2 | _-` q2 |_-` p1 ` q3 p1 q1 . |\ q1, r2, r3 | \ r2| \r3 IN ~~|~~~\~~~~~~~~~ | \ OUT | \ p3 | _-` q3 |_-` p2 ` q2 p2 q1 . |\ q1, r3, r2 | \ r3| \r2 IN ~~|~~~\~~~~~~~~~ | \ OUT | \ p1 | _-` q2 |_-` p3 ` q3 p3 q1 . |\ q1, r3, r2 | \ r3| \r2 IN ~~|~~~\~~~~~~~~~ | \ OUT | \ p2 | _-` q2 |_-` p1 ` q3