Traceback (most recent call last):
File "./prog.py", line 16, in <module>
File "./prog.py", line 4, in num_ways
File "./prog.py", line 12, in find
File "./prog.py", line 12, in find
File "./prog.py", line 12, in find
[Previous line repeated 19 more times]
File "./prog.py", line 8, in find
File "./prog.py", line 8, in find
File "./prog.py", line 8, in find
[Previous line repeated 972 more times]
File "./prog.py", line 7, in find
RecursionError: maximum recursion depth exceeded in comparison