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;

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

            if (S.Substring(0, s.Length) == s) { Console.WriteLine("YES"); return; }
            if (S.Substring((S.Length - s.Length) - 1, s.Length) == s) { Console.WriteLine("YES"); return; }


            int res = 0;
            for (int i = 0; i < s.Length; i++)
            {
                if (S[i] != s[i]) break;
                res++;
            }

            for (int i = 0; i < s.Length; i++)
            {
                if (S[S.Length - 1 - i] != s[s.Length - 1 - i]) break;
                res++;
            }

            if (s.Length <= res)
            {
                Console.WriteLine("YES");
            }
            else
            {
                Console.WriteLine("NO");
            }

        }
    }
}