Who touches the boy?
The girl touches the boy.
    src        edge_attr  dst
0     1   to the left of    7
1     2  to the right of    3
2     2  to the right of   14
3     2  to the right of    6
4     3  to the right of    6
5     3   to the left of    2
6     3   to the left of    4
7     4  to the right of    6
8     4  to the right of    3
9     4  to the right of   14
10    6   to the left of    4
11    6   to the left of    3
12    6   to the left of   14
13    6   to the left of    2
14    7  to the right of    1
15   14   to the left of    4
16   14  to the right of    6
17   14         touching   11
18   14   to the left of    2