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: Accepted)

S=gets.chomp
Sd="keyence"
pointer1=0
for i in 0...S.size do
    if Sd[pointer1]==S[i] then 
        pointer1+=1
        if pointer1==7 then break end
    else break end
end
pointer2=S.size-1
c=0
(S.size-1).downto(0) do |i|
    if Sd[6-c]==S[i] then 
        c+=1
        if c==7 then break end
    else break end
end 
if pointer1+c>=7 then puts "YES" else puts "NO" end