The function return result additional two value (matricies, number, string)

sum.py

def sum(A,B):
	'''
	The function return result 
	additional two matrices.
	parametr A: First variable m x n
	parametr B: Second variable k x p
	...
	return C: result additional
	'''
	# Ensure dimensions are valid for matrix additional
	if 	type(A)==int and type(B)==int or type(A)==str and \
		type(B)==str or type(A)==float and type(B)==float:
		return A+B
	else:
	
		m,n,k,p=len(A),len(A[0]),len(B),len(B[0])
		if m!=k or n!=p:
			raise ArithmeticError('Not the same size.')
	
		# Initial zeros matrix
		C=[[0]*n for _ in range(n)]
		# Perform element by element sum
		for i in range(m):
			for j in range(n):
				C[i][j]=A[i][j]+B[i][j]
	return C

if __name__=='__main__':
	A='Жыве '
	B='Беларусь!'
	print(sum(A,B))