Problem Statement

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?

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.

Constraints

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

Sample Input 1

6 4 3

Sample Output 1

1

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

Sample Input 2

8 3 9

Sample Output 2

4

Sample Input 3

12 3 7

Sample Output 3

0

见题面 Input 部分

见题面 Output 部分