code: def get_size(self, m):
          
          nrow, ncol = 0, 0
          if m[0] == 'F':
              nrow = self.n
          elif m[0] == 'G':
              nrow = self.m
  
          if m[1] == 'x':
              ncol = self.n
          elif m[1] == 'y':
              ncol = self.m
  
          return nrow, ncol
docs: Return the 2-D size of a Jacobian matrix in tuple