What color is the horse behind the other horse?
The horse is black.
    src        edge_attr  dst
0     1      in front of    4
1     1   to the left of    9
2     1   to the left of    2
3     1   to the left of   12
4     1   to the left of   10
5     2  to the right of   12
6     2  to the right of    1
7     2  to the right of   11
8     2  to the right of    5
9     3           behind   11
10    4           behind    1
11    4               on   13
12    4           behind    8
13    4      in front of   11
14    4      in front of   10
15    4          next to   10
16    4             near   10
17    5   to the left of   10
18    5   to the left of    2
19    5   to the left of   12
20    8      in front of    4
21    9  to the right of    1
22    9  to the right of   14
23    9   to the left of   10
24    9  to the right of   16
25   10             near    4
26   10           behind    4
27   10  to the right of    1
28   10  to the right of    9
29   10  to the right of    5
30   10  to the right of   16
31   10  to the right of   11
32   11   to the left of    2
33   11   to the left of   10
34   11   to the left of   12
35   11           behind    4
36   11      in front of    3
37   12  to the right of    1
38   12  to the right of    5
39   12   to the left of    2
40   12  to the right of   11
41   13  to the right of   15
42   14   to the left of    9
43   15   to the left of   13
44   16   to the left of   10
45   16   to the left of    9