What is the door made of?
The door is made of metal.
    src        edge_attr  dst
0     0   to the left of   12
1     0   to the left of   11
2     1   to the left of    9
3     1   to the left of   11
4     1   to the left of    4
5     2   to the left of    7
6     2   to the left of    4
7     3   to the left of   11
8     4  to the right of    2
9     4  to the right of    1
10    4  to the right of   13
11    4   to the left of    9
12    4  to the right of    8
13    5          feeding    9
14    5   to the left of   11
15    5   to the left of    9
16    7  to the right of    2
17    7  to the right of    8
18    8   to the left of    7
19    8   to the left of    4
20    8   to the left of   10
21    8   to the left of   13
22    9  to the right of   10
23    9  to the right of   13
24    9  to the right of    1
25    9  to the right of    4
26    9  to the right of    5
27   10  to the right of    8
28   10   to the left of    9
29   10   to the left of   11
30   11  to the right of   13
31   11  to the right of    0
32   11  to the right of    3
33   11  to the right of    1
34   11  to the right of   10
35   11  to the right of    5
36   12  to the right of    0
37   13  to the right of    8
38   13   to the left of    9
39   13   to the left of   11
40   13   to the left of    4