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;
using System.Collections.Generic;
using System.Text;

namespace codeTester.contest190804
{
    class ProblemA
    {
        static List<long> abc = new List<long>();
        static string answer = "";

        public static void Main(string[] args)
        {
            Input();
            Logic();
            Output();
        }

        static void Input()
        {
            abc = ReadSpaceSeparatedValues();
        }

        public static List<long> ReadSpaceSeparatedValues()
        {
            List<long> values = new List<long>();
            string[] inputs = Console.ReadLine().Split(' ');
            foreach (string input in inputs)
            {
                values.Add(long.Parse(input));
            }

            return values;
        }

        static void Logic()
        {
            long vessel1Size = abc[0];
            long vessel1Water = abc[1];
            long vessel2Water = abc[2];
            long vessel1RemainingCapacity = vessel1Size - vessel1Water;
            answer = Math.Max(vessel2Water - vessel1RemainingCapacity, 0).ToString();
        }

        static void Output()
        {
            Console.WriteLine(answer);
        }
    }
}