What color do you think the screen has?
The screen has gray color.
    src        edge_attr  dst
0     1  to the right of    3
1     1  to the right of    9
2     1  to the right of   12
3     2  to the right of    4
4     3   to the left of   10
5     3  to the right of   12
6     3   to the left of    1
7     4   to the left of    5
8     4   to the left of    2
9     4   to the left of   11
10    4   to the left of    7
11    5   to the left of    8
12    5  to the right of    4
13    6               on   11
14    6        on top of   11
15    7  to the right of    4
16    8  to the right of    5
17    9  to the right of   12
18    9   to the left of    1
19   10  to the right of   12
20   10  to the right of    3
21   11  to the right of    4
22   12   to the left of    3
23   12   to the left of   10
24   12   to the left of    9
25   12   to the left of    1