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 C# (Mono 4.6.2.0) (judge verdict: Accepted)

using System;

namespace A_Transfar
{
    class Program
    {
        static void Main(string[] args)
        {
            int a;
            int b;
            int c;

            //A,B,Cの読み込みと格納
            string num = Console.ReadLine();

            char separator = ' ';
            string[] separated = num.Split(separator);

            a = Convert.ToInt32(separated[0]);
            b = Convert.ToInt32(separated[1]);
            c = Convert.ToInt32(separated[2]);

            //計算
            int d = a - b;
            int remainder = c - d;

            //容器Bに残る余りが0より小さいということは物理的にないので、その場合は0にする
            if(remainder < 0)
            {
                remainder = 0;
            }

            //出力
            Console.WriteLine(remainder);


        }
    }
}