i amhaving this error while playing:
```
I'm sorry, but an uncaught exception occurred.
While running game code:
File "game/code/Book-1/Chapter-7/s00.rpy", line 112, in script
$ b1c07_return += 1
File "game/code/Book-1/Chapter-7/s00.rpy", line 112, in <module>
$ b1c07_return += 1
NameError: name 'b1c07_return' is not defined
-- Full Traceback ------------------------------------------------------------
Full traceback:
File "game/code/Book-1/Chapter-7/s00.rpy", line 112, in script
$ b1c07_return += 1
File "renpy/ast.py", line 1138, in execute
renpy.python.py_exec_bytecode(self.code.bytecode, self.hide, store=self.store)
File "renpy/python.py", line 1122, in py_exec_bytecode
exec(bytecode, globals, locals)
File "game/code/Book-1/Chapter-7/s00.rpy", line 112, in <module>
$ b1c07_return += 1
NameError: name 'b1c07_return' is not defined
Windows-10-10.0.19041 AMD64
Ren'Py 7.6.0.23051307
Vinovella University 0.4.16
Mon Jul 3 18:34:26 2023
```