#include <bits/stdc++.h>
using namespace std;
using ll = long long;
int main() {
  string S;
  cin >> S;
  int length = S.size();
  for (int j = 0; j < length; j++) {
    int out = 0;
    int dead = 0;
    int count = 0;
    for (int i = j; i < length; i++) {
      if (count == 7) {
        if (dead == 0)
          break;
        else {
          dead++;
          break;
        }
      }
      if (count == 6) {
        if (S[i] == 'e') {
          count++;
          out = 0;
          continue;
        } else {
          if (out == 0) {
            dead++;
            out++;
          } else
            out++;
        }
      }
      if (count == 5) {
        if (S[i] == 'c') {
          count++;
          out = 0;
          continue;
        } else {
          if (out == 0) {
            dead++;
            out++;
          } else
            out++;
        }
      }
      if (count == 4) {
        if (S[i] == 'n') {
          count++;
          out = 0;
          continue;
        } else {
          if (out == 0) {
            dead++;
            out++;
          } else
            out++;
        }
      }
      if (count == 3) {
        if (S[i] == 'e') {
          count++;
          out = 0;
          continue;
        } else {
          if (out == 0) {
            dead++;
            out++;
          } else
            out++;
        }
      }
      if (count == 2) {
        if (S[i] == 'y') {
          count++;
          out = 0;
          continue;
        } else {
          if (out == 0) {
            dead++;
            out++;
          } else
            out++;
        }
      }
      if (count == 1) {
        if (S[i] == 'e') {
          count++;
          out = 0;
          continue;
        } else {
          if (out == 0) {
            dead++;
            out++;
          } else
            out++;
        }
      }
      if (count == 0) {
        if (S[i] == 'k') {
          count++;
          out = 0;
          continue;
        } else {
          if (out == 0) {
            dead++;
            out++;
          } else
            out++;
        }
      }
    }
    if (count == 7 && dead < 2) {
      cout << "YES"
           << "\n";
      return 0;
    }
  }
  cout << "NO"
       << "\n";
  return 0;
}
