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 JavaScript (node.js v5.12) (judge verdict: Accepted)

function main(input) {
  const lines = input.split('\n');
  lines.pop();
  lines.forEach(line => {
    const parsed = line.split(' ');
    console.log(fn(
      parseInt(parsed[0], 10),
      parseInt(parsed[1], 10),
      parseInt(parsed[2], 10)
    ));
  });
}

function fn(a, b, c) {
  const answer = c - a + b;
  if (answer < 0) {
    return 0;
  }
  return answer;
}

main(require('fs').readFileSync('/dev/stdin', 'utf8'));