What is the small door made of?
The door is made of metal.
    src        edge_attr  dst
0     0  to the right of   16
1     0  to the right of   13
2     1  to the right of   13
3     1  to the right of   16
4     2   to the left of   16
5     2   to the left of   13
6     2   to the left of    7
7     3   to the left of   12
8     4  to the right of    7
9     4  to the right of   16
10    4  to the right of   13
11    5  to the right of   10
12    5  to the right of   13
13    5  to the right of   12
14    5  to the right of    7
15    5  to the right of   16
16    7   to the left of   15
17    7   to the left of    4
18    7  to the right of    2
19    7  to the right of   10
20    7   to the left of    8
21    7   to the left of    5
22    8  to the right of   16
23    8  to the right of   13
24    8  to the right of    7
25   10   to the left of   15
26   10   to the left of    7
27   10   to the left of   12
28   10   to the left of    5
29   10   to the left of   16
30   12  to the right of   10
31   12   to the left of    5
32   12  to the right of    3
33   12   to the left of   15
34   13   to the left of   14
35   13   to the left of   15
36   13   to the left of    4
37   13   to the left of    8
38   13   to the left of    1
39   13   to the left of    0
40   13   to the left of    5
41   13  to the right of    2
42   14  to the right of   15
43   14  to the right of   13
44   15  to the right of   10
45   15   to the left of   14
46   15  to the right of   12
47   15  to the right of   13
48   15  to the right of    7
49   16   to the left of    1
50   16   to the left of    8
51   16   to the left of    4
52   16  to the right of   10
53   16  to the right of    2
54   16   to the left of    5
55   16   to the left of    0