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 PHP7 (7.0.15) (judge verdict: Wrong Answer)

<?php
    $n = intval(fgets(STDIN));
	$count = 0;
    if($n < 10) {
      $count += $n;
    }
	if($n >= 10 && $n < 100) {
		$count += 0;
    }
	if ($n >= 100 && $n < 1000) {
      $count += ($n-99);
    }
	if ($n >= 1000 && $n < 10000) {
      $count += 0;
    }
	if ($n >= 10000) {
      $count += ($n-9999);
    }
	echo $count; 
	
?>