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)

'use strict'

/////////////////////////////////////
//コピペスペース//////////////////////

//定数
const INF  =  900719925474099 // Math.floor(Number.MAX_SAFE_INTEGER / 10);

//スペース区切りの数字列を数字の配列にして返す
function mapint(line){return line.split(' ').map((v)=>parseInt(v));}

function lower_bound(d,a,b,e){
    for(var c;1<b-a;)
        d[c=0|(a+b)/2]<e ? a=c : b=c;
    return d[a]<e?b:a
};

const N109 = 1000000000;
const MOD = N109+7;

//コピペスペース//////////////////////
/////////////////////////////////////

function Main(input){
	let temp = input.trim();
	let abc = mapint(temp);
	let a = abc[0];
	let b = abc[1];
	let c = abc[2];

	let ans = c-(a-b);
	if(ans<0) ans = 0;
	console.log(ans);
}

Main(require("fs").readFileSync("/dev/stdin", "utf8"));