+---+
| 5 |
+---+
| | +---+---+----+
| | | 2 | 3 | 4 |
| 1 | +---+---+----+
| | |
| | <--------------+
+---+
+---+
| 5 |
+---+
| | +---+---+----+
| | | 2 | 3 | 4 |
| 1 | +---+---+----+
| | |
| | <--------------+
+---+