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)

use std::io;
use std::str::FromStr;

fn main() {
    let stdin = io::stdin();

    let mut buf = String::new();
    stdin.read_line(&mut buf).ok();
    let mut input = buf.split_whitespace().map(|i| usize::from_str(i).unwrap());
    let (youki, mizu1, mizu2) = (input.next().unwrap(), input.next().unwrap(), input.next().unwrap());

    let mut result = 0;

    if (youki < (mizu1 + mizu2)) {
        result = mizu2 - (youki - mizu1);
    }

    println!("{}", result);
}