Chocolate stack

A shop has a stack of chocolate boxes each containing a positive number of chocolates. Initially, the stack is empty. During the next N minutes, either of these two things may happen:

$$ The box of chocolates on top of the stack gets sold

You receive a box of chocolates from the warehouse and put it on top of the stack.

Determine the number of chocolates in the sold box each time he sells a box.

Notes

If C$[$i$]=0,$ he sells a box. If C$[$i$]>0,$ he receives a box containing C$[$I$]$ chocolates.

It is confirmed that he gets a buyer only when he has a non$-$ empty stack.

The capacity of the stack is infinite.