Where is the sheep?
The sheep is in the pen.
    src        edge_attr  dst
0     2   to the left of   10
1     2  to the right of    4
2     2   to the left of   12
3     3   to the left of   10
4     3  to the right of    4
5     4   to the left of    2
6     4   to the left of    3
7     6  to the right of    8
8     6  to the right of   11
9     7  to the right of   11
10    7  to the right of    8
11    8   to the left of    6
12    8   to the left of    7
13    9  to the right of   11
14   10  to the right of    3
15   10  to the right of    2
16   11   to the left of    9
17   11               in    1
18   11   to the left of    7
19   11   to the left of    6
20   12  to the right of    2