What is the height of the gate?
The gate is tall.
    src        edge_attr  dst
0     0  to the right of    4
1     0  to the right of    7
2     1  to the right of    7
3     2  to the right of   10
4     2  to the right of    7
5     4  to the right of    7
6     4   to the left of    0
7     5  to the right of   10
8     7   to the left of    0
9     7   to the left of    2
10    7   to the left of    4
11    7  to the right of   10
12    7   to the left of    1
13    9               on    8
14   10   to the left of    2
15   10   to the left of    7
16   10   to the left of    5