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 Rust (1.42.0) (judge verdict: Accepted)

use whiteread::parse_line;

fn main() {
    let s: String = parse_line().unwrap();
    let keyence = "keyence";
    let mut ans = "NO";

    if s.starts_with(keyence) || s.ends_with(keyence) {
        ans = "YES";
    } else {
        let mut s = s.chars();
        let mut k = keyence.chars();
        let mid: Option<char> = loop {
            if let Some(c) = k.next() {
                if s.next() != Some(c) {
                    break Some(c);
                }
            } else {
                break None;
            }
        };
        if {
            loop {
                if let Some(c) = k.next_back() {
                    if s.next_back() != Some(c) {
                        break false;
                    }
                } else if mid.is_some() {
                    if s.next_back() == mid {
                        break true;
                    } else {
                        break false;
                    }
                } else {
                    break true;
                }
            }
        } {
            ans = "YES";
        }
    }
    println!("{}", ans);
}