How to create a polars data frame from a dictionary which has unequal length values?

I have a dictionary as:

ex_dict = {'A': ['false',
  'true',
  'false',
  'false',
  'false',
  'true',
  'true',
  'false',
  'false'],
 'B': ['false',
  'false',
  'true',
  'false',
  'false',
  'false'],
  'C': ['false',
  'true',
  'true',
  'false',
  'false',
  'false',
  'false',
  'false',
  'true']}

I'm creating a dataframe as:

pl.DataFrame(ex_dict)

on executing it gives an error as:

ShapeError: Could not create a new DataFrame from Series. The Series have different lengths.Got [shape: (9,)

How to create a polars dataframe in these scenarios ?