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 (1.15.1) (judge verdict: Accepted)

fn read_as_string() -> String{
    let mut s = String::new();
    std::io::stdin().read_line(&mut s).unwrap();
    s.trim().to_string()
}

fn main(){
    let line = read_as_string();
    let keyence = String::from("keyence");

    for i in 1..keyence.len(){
        let(first, last) = keyence.split_at(i);
        //println!("first = {}, last = {}", first, last);
        let first_poses: Vec<_> = line.match_indices(first).map(|x| x.0).collect();
        let last_poses: Vec<_> = line.match_indices(last).map(|x| x.0).collect();
        if first_poses.len() == 0  || last_poses.len() == 0{ continue;}
        //println!("fposes = {:?}, lposes = {:?}", first_poses, last_poses);
        for first_pos in &first_poses{
            for last_pos in &last_poses{
                if *first_pos + first.len() <= *last_pos{
                    let pdust = *first_pos;
                    let mdust = *last_pos - *first_pos - first.len();
                    let sdust = line.len() - *last_pos - last.len();
                    //println!("prefix = {}, middle={}, suffix={}", pdust, mdust, sdust);
                    if (pdust == 0 && mdust == 0) ||
                        (mdust == 0 && sdust == 0) ||
                        (pdust == 0 && sdust == 0){
                            println!("YES");
                            return;
                        }
                }
            }
        }

    }
    println!("NO");
}