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: Runtime Error)

using System;
class stairs{
  public static void Main(){
    int n = int.Parse(Console.ReadLine());
    String[] str = Console.ReadLine().Split(' ');
    bool flag = true;
    bool pflag = true;
    int[] num = new int[n];
    for(int i=0; i<n; i++){
      num[i] = int.Parse(str[i]);
    }
    for(int i=1; i<n; i++){
      if(flag){
        if(num[i-1] > num[i]){
          flag = false;
        }
        if(num[i-1] < num[i]){
          flag = true;
        }
      }
      else{
        if(num[i-1] > num[i]){
          Console.WriteLine("NO");
          pflag = false;
          break;
        }
        if(num[i-1] < num[i]){
          flag = true;
        }
      }
    }
    if(pflag)
      Console.WriteLine("YES");
  }
}