What is the white cow walking towards?
The cow is walking towards the river.
    src        edge_attr  dst
0     1      in front of    5
1     4    drinking from    2
2     4   to the left of    7
3     7  to the right of    4
4     8               in    1
5     9               by   10
6     9               in    1
7     9   to the left of   13
8    10   to the left of   13
9    10               in    1
10   11   to the left of   12
11   12  to the right of   11
12   13               in    1
13   13  to the right of   10
14   13  to the right of    9
15   14  walking towards    2
16   14               in    1