How to made a limit value at 10 and after that don't count even if I add more value in cell

Help please!

I need a formula with...

Ex.

Limit apple bucket at 10

If I buy 11 apple it have to limit at 10.

If I sell 3 apple it have to count 7 apple not 9.

Buy more 5 count to 10 not 12 but if buy 1 count at 8.

Sell more 1,2,3 minus from limit 10 in the bucket.

And after that circle this loop.

Thank a lot !!