#include <bits/stdc++.h>
using namespace std;
const long long INF = 1LL << 60;
int main() {
  string S;
  cin >> S;
  S.append("a");
  int size = S.size();
  bool final_frg = false;
  for (int i = 0; i < size; i++) {
    int num;
    int bet;
    bool between = true;
    bool frg0 = false;
    bool frg1 = false;
    bool frg2 = false;
    bool frg3 = false;
    bool frg4 = false;
    bool frg5 = false;
    bool frg6 = false;
    for (int j = i; j < size; j++) {
      if (frg0 && between) {
        if (frg1 && between) {
          if (frg2 && between) {
            if (frg3 && between) {
              if (frg4 && between) {
                if (frg5 && between) {
                  if (frg6 && between) {
                    final_frg = true;
                  } else {
                    if (S[j] == 'e') {
                      frg6 = true;
                      if (j != num + 1) {
                        bet++;
                      }
                      if (bet > 1) {
                        between = false;
                      }
                      num = j;
                    }
                  }
                } else {
                  if (S[j] == 'c') {
                    frg5 = true;
                    if (j != num + 1) {
                      bet++;
                    }
                    if (bet > 1) {
                      between = false;
                    }
                    num = j;
                  }
                }
              } else {
                if (S[j] == 'n') {
                  frg4 = true;
                  if (j != num + 1) {
                    bet++;
                  }
                  if (bet > 1) {
                    between = false;
                  }
                  num = j;
                }
              }
            } else {
              if (S[j] == 'e') {
                frg3 = true;
                if (j != num + 1) {
                  bet++;
                }
                if (bet > 1) {
                  between = false;
                }
                num = j;
              }
            }
          } else {
            if (S[j] == 'y') {
              frg2 = true;
              if (j != num + 1) {
                bet++;
              }
              if (bet > 1) {
                between = false;
              }
              num = j;
            }
          }
        } else {
          if (S[j] == 'e') {
            frg1 = true;
            if (j != num + 1) {
              bet++;
            }
            if (bet > 1) {
              between = false;
            }
            num = j;
          }
        }
      } else {
        if (S[j] == 'k') {
          frg0 = true;
          int num = j;
          if (j != 0) {
            bet++;
          }
        }
      }
    }
  }
  if (final_frg) {
    cout << "YES" << endl;
  } else {
    cout << "NO" << endl;
  }
}
