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 Haskell (GHC 7.10.3) (judge verdict: Accepted)

head0 :: String -> String -> (String,String)
head0 [] _ = ([],[])
head0 _ [] = (['a'],[])
head0 (k:ey) (l:ls) = if k == l then head0 ey ls else (k:ey,l:ls)

main :: IO ()
main = do
  l <-  getLine 
  if (fst $ head0 (reverse $ fst $ head0 "keyence" l) (reverse $ snd $ head0 "keyence" l)) == [] 
    then putStrLn "YES" else putStrLn "NO"