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 Ruby (2.3.3) (judge verdict: Wrong Answer)

S = gets

array = 'a'.upto('y').to_a

flag = 0
(0..26).each do |i|
  if array[i] == S
    flag = 1
  elsif flag == 1 and i != 25
    puts array[i]
    break
  elsif i == 25
    puts "z"
    break
  end
end