Problem:
Score : 100 points

Problem Statement

Given is a lowercase English letter C that is not z. Print the letter that follows C in alphabetical order.

Constraints

C is a lowercase English letter that is not z.

Input

Input is given from Standard Input in the following format:

C

Output

Print the letter that follows C in alphabetical order.

Sample Input 1

a

Sample Output 1

b

a is followed by b.

Sample Input 2

y

Sample Output 2

z

y is followed by z.

Solution in PHP7 (7.0.15) (judge verdict: Wrong Answer)

<?php
    fscanf(STDIN, "%d %d %d", $n, $k, $m);
    $array = explode(' ', trim(fgets(STDIN)));
    $x = $m * $n ;
    for($i = 0 ; $i < count($array); $i++){
        $x -= $array[$i];
    }
    if($x <= $k){
        echo $x;
    }elseif($x > $k){
        echo -1;
    }
?>