A mathematical puzzle of a coin

Divide it into two piles, 5 in pile A and 7 in pile B, and then turn all the piles upside down with 5.

The analysis is as follows:

If A is 5 positive and 0 negative, B is 0 positive, and A is 0 positive after turning.

If A is 4 plus 1 minus, B is 1 plus, and A is 1 plus after rotation.

If A is 3 positive and 2 negative, B is 2 positive, and A is 2 positive after turning.

If A is 2 plus 3 minus, B is 3 plus, and A is 3 plus after turning.

If A is 1 positive 4 negative, then B is positive 4, and A is positive 4 after the rotation.

If A is 0 plus 5 minus, B is 5 plus, and A is 5 plus after turning.