Problem:
Score : 100 points

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?

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 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

Solution in PHP (5.6.30) (judge verdict: Accepted)

<?php
const INPUT_DELIMITER = " ";

// 標準入力
$input = fgets(STDIN);
$inputArray = explode(INPUT_DELIMITER, $input);

$A = $inputArray[0];
$B = $inputArray[1];
$C = $inputArray[2];

$Ans = $C - ($A - $B);

if ($Ans >= 0) {
    echo $Ans;
} else {
    echo 0;
}