#include <bits/stdc++.h>
using namespace std;
string s;
bool check() {
  int e = 3, n = 1, c = 1, y = 1, k = 1;
  for (int i = 0; i < s.size(); i++) {
    if (s[i] == 'e') e--;
    if (s[i] == 'n') n--;
    if (s[i] == 'c') c--;
    if (s[i] == 'y') y--;
    if (s[i] == 'k') k--;
  }
  return (e <= 0 && n <= 0 && c <= 0 && y <= 0 && k <= 0);
}
int main() {
  getline(cin, s);
  cout << (check() ? "YES" : "NO");
}
