Problem:
Score : 100 points

Problem Statement

Given a lowercase English letter c, determine whether it is a vowel. Here, there are five vowels in the English alphabet: a, e, i, o and u.

Constraints

c is a lowercase English letter.

Input

The input is given from Standard Input in the following format:

c

Output

If c is a vowel, print vowel. Otherwise, print consonant.

Sample Input 1

a

Sample Output 1

vowel

Since a is a vowel, print vowel.

Sample Input 2

z

Sample Output 2

consonant

Sample Input 3

s

Sample Output 3

consonant

Solution in Ruby (2.3.3) (judge verdict: Wrong Answer)

s = gets.chomp

index = 0
result = true

while index < s.size-1
  if s[index] == "d"
    if s[index..index+6] == "dreamer" && s[index+7] != "a"
      index += 7
      next
    elsif s[index..index+4] == "dream"
      index += 5
      next
    else
      result = false
      break
    end
  elsif s[index] == "e"
    if s[index..index+5] == "eraser"
      index += 6
      next
    elsif s[index..index+4] == "erase"
      index += 5
      next
    else
      result = false
      break
    end
  else
    result = false
    break
  end
end

puts result ? "YES" : "NO"