We have two bottles for holding water.
Bottle 1 can hold up to A milliliters of water, and now it contains B milliliters of water.
Bottle 2 contains C milliliters of water.
We will transfer water from Bottle 2 to Bottle 1 as much as possible.
How much amount of water will remain in Bottle 2?

-----Constraints-----
- All values in input are integers.
- $1 \leq B \leq A \leq 20$
- $1 \leq C \leq 20$

-----Input-----
Input is given from Standard Input in the following format:
A B C

-----Output-----
Print the integer representing the amount of water, in milliliters, that will remain in Bottle 2.

-----Sample Input-----
6 4 3

-----Sample Output-----
1

We will transfer two milliliters of water from Bottle 2 to Bottle 1, and one milliliter of water will remain in Bottle 2.

见题面

见题面