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 OCaml (4.02.3) (judge verdict: Wrong Answer)

Scanf.scanf " %s" @@ fun s ->
  let n = String.length s in
  for i=0 to n-1 do
    for j=i to n-1 do
      let t = String.(sub s 0 i ^ sub s j (n-j)) in
      print_endline t;
      if t = "keyence" then (
        print_endline "YES"; exit 0)
    done
  done;
  print_endline "NO"