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: Wrong Answer)

using System;
using System.Text;
using System.Linq;

class Program
{
    static void Main(string[] args) {
#if DEBUG
        System.Diagnostics.Debug.WriteLine("-----TextFile1");
        System.Diagnostics.Debug.WriteLine(process("../TextFile1.txt"));
        System.Diagnostics.Debug.WriteLine("-----TextFile2");
        System.Diagnostics.Debug.WriteLine(process("../TextFile2.txt"));
        System.Diagnostics.Debug.WriteLine("-----TextFile3");
        System.Diagnostics.Debug.WriteLine(process("../TextFile3.txt"));
#endif

#if !DEBUG
        String ret = process(new System.IO.StreamReader(Console.OpenStandardInput()));
        Console.WriteLine(ret);
#endif
    }

    static string process(string filePath) {
        using (var input = new System.IO.StreamReader(filePath)) {
            if(input.EndOfStream) return "NO PROC";
            return process(input);
        }
    }

    static string process(System.IO.TextReader input) {
        var s     = input.ReadLine();
        var spl   = s.Split(' ');
        int a     = int.Parse(spl[0]);
        int b     = int.Parse(spl[1]);
        int c     = int.Parse(spl[2]);

        return Math.Min( (c - (a - b)), 0).ToString();
    }

    
    static int[] ToIntArray(string strs, int n) {
        int[] ret = new int[n];
        var spl =strs.Split(' ');
        for (int i = 0; i < n; i++) ret[i] = int.Parse(spl[i]);
        return ret;
    }
}