What color is the clock that is not clean?
The clock is brown.
    src        edge_attr  dst
0     0  to the right of   11
1     3  to the right of    7
2     5   to the left of    9
3     5   to the left of   12
4     7   to the left of    3
5     9  to the right of   12
6     9  to the right of    5
7    11    surrounded by   10
8    11   to the left of    0
9    11    surrounded by    6
10   12  to the right of    5
11   12   to the left of    9