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___Transfer
{
    class Program
    {
        static void Main (string[] args)
        {
            var input = Console.ReadLine ().Split (' ');
            var a = int.Parse (input[0]);
            var b = int.Parse (input[1]);
            var c = int.Parse (input[2]);
            var ans = c - (a - b);
            if (ans >= 0)
            {
                Console.WriteLine (ans);
            }
            else
            {
                Console.WriteLine (0);
            }
        }
    }
}