What color do you think the street sign is?
The street sign is green.
    src        edge_attr  dst
0     0        on top of   15
1     1            above    4
2     1   to the left of   11
3     2            above    4
4     3  to the right of    4
5     3  to the right of   13
6     4            below    2
7     4            below    1
8     4   to the left of    3
9     7   to the left of   12
10    7        parked on   17
11    7      in front of    8
12    8           behind    7
13   11  to the right of   13
14   11  to the right of    1
15   12      in front of    4
16   12  to the right of   17
17   12  to the right of    7
18   12   to the left of   16
19   13   to the left of   11
20   13   to the left of    3
21   16  to the right of   12
22   17   to the left of   12