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::{stdin, stdout, Write};

fn read_line()-> String {
    let mut s = String::new();
    let _ = stdout().flush();
    stdin().read_line(&mut s).expect("Did not enter a correct string");
    if let Some('\n') = s.chars().next_back() {
        s.pop();
    }
    if let Some('\r') = s.chars().next_back() {
        s.pop();
    }
    s
}

fn read_num_line()->Vec<i32> {
    let line = read_line();
    let s_vec = line.split(" ").collect::<Vec<&str>>();
    let mut n_vec = Vec::new();
    for s in s_vec {
        let num: i32 = s.parse().unwrap();
        n_vec.push(num);
    }
    n_vec
}

fn main() {
    let line = read_num_line();
    let a = line[0];
    let b = line[1];
    let c = line[2];
    let result = c-a+b;
    println!("{}", if result < 0 {0}else{result});
}