Problem:
Score : 200 points

Problem Statement

A string is called a KEYENCE string when it can be changed to keyence by removing its contiguous substring (possibly empty) only once.

Given a string S consisting of lowercase English letters, determine if S is a KEYENCE string.

Constraints

The length of S is between 7 and 100 (inclusive).

S consists of lowercase English letters.

Input

Input is given from Standard Input in the following format:

S

Output

If S is a KEYENCE string, print YES; otherwise, print NO.

Sample Input 1

keyofscience

Sample Output 1

YES

keyence is an abbreviation of key of science.

Sample Input 2

mpyszsbznf

Sample Output 2

NO

Sample Input 3

ashlfyha

Sample Output 3

NO

Sample Input 4

keyence

Sample Output 4

YES

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

s = STDIN.gets.chomp.chars
target = ['k', 'e', 'y', 'e', 'n', 'c', 'e']
num = 0
successive = false
index = 0

s.each do |char|
  if char == target[index]
    index += 1
    successive = false
  elsif successive == false
    num += 1
    successive = true
  end
end

if index == 7 && num <= 1
  puts 'YES'
else
  puts 'NO'
end