What color is the door?
The door is red.
    src        edge_attr  dst
0     1  to the right of   15
1     1   to the left of    3
2     3  to the right of   15
3     3  to the right of    1
4     4   to the left of    8
5     4   to the left of    6
6     4   to the left of   11
7     6  to the right of   11
8     6  to the right of    4
9     7  to the right of   15
10    8  to the right of    4
11    8   to the left of   11
12    9  to the right of   16
13   11  to the right of    4
14   11   to the left of    6
15   11  to the right of    8
16   13   to the left of   16
17   15   to the left of    7
18   15   to the left of    3
19   15   to the left of    1
20   16  to the right of   13
21   16   to the left of    9