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 C# (Mono 4.6.2.0) (judge verdict: Accepted)

using System;
using System.Linq;
using System.Text.RegularExpressions;

namespace KPC2019
{
    class B2
    {
        static void Main(string[] args)
        {
            var S = Console.ReadLine();

            // keymoonさんの回答と同じ書き方を試す
            // https://atcoder.jp/contests/keyence2019/submissions/10724495

            Console.WriteLine(
                Regex.IsMatch(S, "^.*keyence$") ||
                Regex.IsMatch(S, "^k.*eyence$") ||
                Regex.IsMatch(S, "^ke.*yence$") ||
                Regex.IsMatch(S, "^key.*ence$") ||
                Regex.IsMatch(S, "^keye.*nce$") ||
                Regex.IsMatch(S, "^keyen.*ce$") ||
                Regex.IsMatch(S, "^keyenc.*e$") ||
                Regex.IsMatch(S, "^keyence.*$") ? "YES" : "NO");
        }
    }
}