Problem:
Score : 100 points

Problem Statement

There is an N-car train.

You are given an integer i. Find the value of j such that the following statement is true: "the i-th car from the front of the train is the j-th car from the back."

Constraints

1 \leq N \leq 100

1 \leq i \leq N

Input

Input is given from Standard Input in the following format:

N i

Output

Print the answer.

Sample Input 1

4 2

Sample Output 1

3

The second car from the front of a 4-car train is the third car from the back.

Sample Input 2

1 1

Sample Output 2

1

Sample Input 3

15 11

Sample Output 3

5

Solution in PHP (5.6.30) (judge verdict: Accepted)

<?php

$line = fgets(STDIN); // 標準入力からの入力値を変数に代入
$array = explode(" ", $line); // 取得した入力値を半角スペースで分解

$l=1;
foreach($array as $value){
    if ($l==1){
        $N = $value;
    }else {
        $i = $value;
    }
    $l++;
}

$x = $N - $i + 1;
echo $x;

?>