code not working and instead returning value 3221225477

hello, i have a bunch of exercices to do in C, but somehow nothing i write works and i have no idea why. when i looked it up all i found was that it appears when you try to open u file that doesn't exist or using pointers that lead nowhere and i did neither. any help or hint would ne much appreciated Edit: Wow, thanks for the fast and clear answers, i will look more into pointers and what they do #include #include int a;