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 Fortran (gfortran v4.8.4) (judge verdict: Wrong Answer)

program main
  implicit none

  character(len=100) :: s
  character(len=7) :: c
  integer :: n, i

  read(*,*) s

  n = len_trim(s)
  c = 'keyence'

  if(index(s,c) /= 0) then
     if (index(s,c) == 1 .or. index(s,c, back=.true.) == n-6) then
        write(*,*) 'YES'
     else
        write(*,*) 'NO'
     end if
     stop
  else
     do i = 1, 7
        if(index(s,c(1:i)) == 1 .and. index(s,c(i+1:7), back=.true.) == n-i) then
           write(*,*) 'YES'
           stop
        end if
     end do
     
     write(*,*) 'NO'
  end if
end program main