Problem:
Score : 100 points

Problem Statement

Snuke has N integers: 1,2,\ldots,N.
He will choose K of them and give those to Takahashi.

How many ways are there to choose K consecutive integers?

Constraints

All values in input are integers.

1 \leq K \leq N \leq 50

Input

Input is given from Standard Input in the following format:

N K

Output

Print the answer.

Sample Input 1

3 2

Sample Output 1

2

There are two ways to choose two consecutive integers: (1,2) and (2,3).

Sample Input 2

13 3

Sample Output 2

11

Solution in Rust (1.15.1) (judge verdict: Accepted)

use std::io::Read;
use std::io::{stdout, BufWriter, Write};

fn main() {
    let mut buf = String::new();

    // stdinから全てbufに読み込む
    std::io::stdin().read_to_string(&mut buf).unwrap();

    // 読み込んだ文字列をスペースで分解する
    let mut iter = buf.split_whitespace();

    // about n
    let n: usize = iter.next().unwrap().parse().unwrap();
    // about k
    let k: usize = iter.next().unwrap().parse().unwrap();

    // ans
    let ans: usize = n - k + 1;

    // 出力
    let out = stdout();
    let mut out = BufWriter::new(out.lock());
    writeln!(out, "{}", ans).unwrap();
}