What color is the backpack to the left of the people, gray or purple?
The backpack is gray.
    src        edge_attr  dst
0     0   to the left of   11
1     0   to the left of    6
2     0   to the left of    7
3     1   to the left of   12
4     2  to the right of    4
5     2               on   10
6     2  to the right of    5
7     3   to the left of    4
8     3   to the left of   10
9     3   to the left of    9
10    3   to the left of   12
11    4   to the left of   12
12    4   to the left of    8
13    4   to the left of    2
14    4   to the left of    6
15    4  to the right of    3
16    5               on   10
17    5   to the left of    2
18    5   to the left of   12
19    6  to the right of    0
20    6  to the right of    4
21    6  to the right of   13
22    6   to the left of    8
23    7  to the right of   13
24    7  to the right of    0
25    8  to the right of    4
26    8  to the right of    6
27    9  to the right of    3
28   10  to the right of    3
29   11  to the right of   13
30   11  to the right of    0
31   12  to the right of    5
32   12  to the right of    1
33   12  to the right of    4
34   12  to the right of    3
35   13          wearing    0
36   13   to the left of    7
37   13   to the left of    6
38   13   to the left of   11