Is there a clock or a flag in the scene?
Yes, there is a clock.
    src        edge_attr  dst
0     0  to the right of   20
1     0  to the right of    2
2     0  to the right of   15
3     0  to the right of   11
4     0  to the right of    6
5     2   to the left of   10
6     2   to the left of    8
7     2   to the left of    9
8     2   to the left of    0
9     2   to the left of   18
10    3   to the left of   20
11    3  to the right of   12
12    4   to the left of    5
13    4   to the left of   13
14    5   to the left of   14
15    5  to the right of    4
16    6   to the left of    0
17    6  to the right of   12
18    6   to the left of    9
19    6   to the left of    8
20    6   to the left of   18
21    6  to the right of   17
22    7   to the left of   13
23    7   to the left of   14
24    8  to the right of   11
25    8  to the right of    2
26    8  to the right of    6
27    9  to the right of    2
28    9               on    8
29    9  to the right of    6
30    9  to the right of   11
31   10  to the right of    2
32   10               on    0
33   11   to the left of    8
34   11   to the left of    9
35   11   to the left of   18
36   11  to the right of   16
37   11   to the left of    0
38   12       walking up    7
39   12   to the left of    3
40   12   to the left of    6
41   13  to the right of    4
42   13  to the right of    7
43   14  to the right of    7
44   14  to the right of    5
45   14       walking up   13
46   15   to the left of    0
47   15               on    1
48   15  to the right of   16
49   16   to the left of   19
50   16   to the left of   11
51   16   to the left of   15
52   17   to the left of    6
53   18  to the right of   11
54   18  to the right of    2
55   18  to the right of    6
56   19  to the right of   16
57   20  to the right of    3
58   20   to the left of    0