Problem:
Score : 100 points

Problem Statement

You went shopping to buy cakes and donuts with X yen (the currency of Japan).

First, you bought one cake for A yen at a cake shop.
Then, you bought as many donuts as possible for B yen each, at a donut shop.

How much do you have left after shopping?

Constraints

1 \leq A, B \leq 1 000

A + B \leq X \leq 10 000

X, A and B are integers.

Input

Input is given from Standard Input in the following format:

X
A
B

Output

Print the amount you have left after shopping.

Sample Input 1

1234
150
100

Sample Output 1

84

You have 1234 - 150 = 1084 yen left after buying a cake.
With this amount, you can buy 10 donuts, after which you have 84 yen left.

Sample Input 2

1000
108
108

Sample Output 2

28

Sample Input 3

579
123
456

Sample Output 3

0

Sample Input 4

7477
549
593

Sample Output 4

405

Solution in Rust (1.15.1) (judge verdict: Runtime Error)

fn read<T: std::str::FromStr>() -> T {
    let mut s = String::new();
    std::io::stdin().read_line(&mut s).ok();
    s.trim().parse().ok().unwrap()
}

fn pattern_count(a: i32, b: i32, c: i32, x: i32) -> i32 {
    let mut found: i32 = 0;
    for i in 0..(a + 1) {
        for j in 0..(b + 1) {
            for k in 0..(c + 1) {
                if i * 500 + j * 100 + k * 50 == x {
                    found = found + 1;
                }
            }
        }
    }
    return found;
}

fn main() {
    let a: i32 = read();
    let b: i32 = read();
    let c: i32 = read();
    let x: i32 = read();
    let count: i32 = pattern_count(a, b, c, x);
    println!("{}", count);
}