What is the device in the restaurant?
The device is a phone.
    src        edge_attr  dst
0     0               in    1
1     0   to the left of    3
2     0  to the right of    2
3     0   to the left of    4
4     2               in    1
5     2   to the left of    0
6     3   to the left of    5
7     3               in    1
8     3  to the right of    0
9     4  to the right of    0
10    5  to the right of    3
11    5               in    1