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::io::BufRead;

fn main() {
    let stdin = io::stdin();
    let mut stdin = stdin.lock();
    
    let (a, b, c) = {
        let mut input = String::new();
        stdin.read_line(&mut input).unwrap();
        let mut input = input.trim().split_whitespace();
        (
            input.next().unwrap().parse::<u32>().unwrap(),
            input.next().unwrap().parse::<u32>().unwrap(),
            input.next().unwrap().parse::<u32>().unwrap(),
        )
    };

    let d = a - b;
    
    println!("{}", c.saturating_sub(d) );
}