#include <bits/stdc++.h>
using namespace std;
int main() {
  string s;
  cin >> s;
  char a[110];
  int size = s.size();
  int c1 = 0;
  int e3 = 0;
  int k1 = 0;
  int n1 = 0;
  int y1 = 0;
  for (int i = 0; i < size; i++) {
    if (s[i] == 'c') {
      c1++;
    }
    if (s[i] == 'e') {
      e3++;
    }
    if (s[i] == 'k') {
      k1++;
    }
    if (s[i] == 'n') {
      n1++;
    }
    if (s[i] == 'y') {
      y1++;
    }
  }
  if (c1 > 0 && e3 > 2 && k1 > 0 && n1 > 0 && y1 > 0) {
    cout << "YES"
         << "\n";
  } else {
    cout << "NO"
         << "\n";
  }
}
