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++14 (GCC 5.4.1) (judge verdict: Wrong Answer)

#include <iostream>
#include <string>
using namespace std;

int main() {
    string s;
    cin >> s;

    string t = "keyence";
    //cout << ("" == "") << endl; 
    bool first = false;
    for (int i = 1; i <= 7; i++) {
        string t1 = t.substr(0, i);
        string t2 = t.substr(i, 7 - i);
        for (int j = 0; j < s.size() - i + 1; j++) {
            if (s.substr(j, i) == t1 && !first) {
                first = true;
                if (i == 7) {
                    cout << "YES" << endl;
                    return 0;
                }
                continue;
            }

            if (s.substr(j, 7 - i) == t2 && first) {
                cout << "YES" << endl;
                return 0;
            }
        }
    }

    cout << "NO" << endl;
    return 0;
}