How heavy is the gray smoke?
The smoke is heavy.
    src        edge_attr  dst
0     0    coming out of    1
1     0      coming from    1
2     0  to the right of    7
3     0  to the right of    3
4     1   to the left of    9
5     1  to the right of    3
6     1  to the right of   10
7     3   to the left of    0
8     3   to the left of    1
9     3  to the right of   10
10    5  to the right of   10
11    5   to the left of    8
12    5   to the left of    6
13    6   to the left of    8
14    6  to the right of    5
15    6  to the right of   10
16    7               in    4
17    7   to the left of    0
18    8  to the right of   10
19    8  to the right of    5
20    8  to the right of    6
21    9  to the right of    1
22   10   to the left of    8
23   10   to the left of    6
24   10   to the left of    1
25   10   to the left of    5
26   10   to the left of    3