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 Rust (1.15.1) (judge verdict: Accepted)

/// 1行の文字を空白で分割してVec<T>にする。
fn read_split<T : std::str::FromStr>() -> Vec<T> {
    let mut input = String::new();
    std::io::stdin().read_line(&mut input).unwrap();
    input.trim().split_whitespace().map(|x| x.parse().ok().unwrap()).collect()
}

fn main() {
    let input : Vec<i32> = read_split();
    let water = input[1] + input[2];
    let answer : i32;
    if water < input[0] {
        answer = 0;
    } else {
        answer = water - input[0];
    }
    println!("{}", answer);
}