Janette5 : Thank you very much . The discovery of distinct alterable values was brilliant. In my game the alterable values A and B serve for other events. But it is not a problem, I just need to have patience to replace them with alterable values AF AG etc.
Only if you have time, check this in the whole project, if you want you can also modify it and suggest me if, for example, the story I put in the demo is childish or in incorrect English, if you can improve collisions sprites etc. etc.