1:                           X4
2:
3:   7 7 5
4:         7  3 5 3 5 3
5: 5                    5
6:

1:                        X2
2:
3:
4:   5 5 3
5:         5  1 3 1 3 1
6: 3                    3

1:                       X2
2:
3:  7 7 5
4:        7  3 5 3 5 3
5:5                    5
6:

1:
2:                                    ^
3:                                    5 5
4:  7 7 5   7 7   5 7  5 5 5 5 5           7 5
5:        7     7                8 5           8
6: 5