[Closed] What is the issue here in the code?

Guys

i am learning to write procedures and, i am kind of stuck, trying to execute this.. I am not sure why is the error

CREATE PROCEDURE CreateIdentity
 (
  @AliasName varchar(50),
  @id int output
 )
AS

BEGIN
  SELECT @id = ISNULL(max(IdentifiedObjectId),0) + 1 
  from A.IdentifiedObject
  INSERT INTO A.IdentifiedObject 
  VALUES (@AliasName, '', '', '', @AliasName, '', @id, NULL)
END
GO


DECLARE @id int
EXEC CreateIdentity ENTITY, @id output

print @id

ERROR::: Msg 8114, Level 16, State 5, Procedure CreateIdentity, Line 0 Error converting data type nvarchar to int.