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 Python (3.4.3) (judge verdict: Accepted)

import sys
INPUT = sys.stdin.readline
#入力関数
def SORO_INT(): return int(INPUT())
def MULT_INT_LIST(): return list(map(int, INPUT().split()))
def MULT_INT_MAP(): return map(int, INPUT().split())
def SORO_STRING(): return INPUT()
def MULT_STRING(): return INPUT().split()

A,B,C = MULT_INT_LIST()

ans = C-(A-B)
if ans<0:
  ans = 0
print(ans)