#include <bits/stdc++.h>
using namespace std;
using ll = long long;
int main() {
  ll a = 0, b = 0, c = 0, d = 0, e = 0, f = 0, g = 0, h = 0, ans = 0;
  ll n;
  ll memo[1003][1003] = {};
  ll memo2[1003][1003] = {};
  char tmp;
  string s;
  cin >> s;
  for (int i = 0; i < s.length(); i++) {
    if (a == 7 && b == 1) {
      cout << "NO" << endl;
      return 0;
    }
    if (a == 6 && b == 0 && s[i] != 'e') {
      b = 1;
      while (s[i] != 'e' && i < s.length()) {
        i++;
      }
      i--;
    } else if (a == 6 && s[i] == 'e') {
      a++;
    } else if (a == 6 && b == 1 && s[i] != 'e') {
      cout << "NO" << endl;
      return 0;
    }
    if (a == 5 && b == 0 && s[i] != 'c') {
      b = 1;
      while (s[i] != 'c' && i < s.length()) {
        i++;
      }
      i--;
    } else if (a == 5 && s[i] == 'c') {
      a++;
    } else if (a == 5 && b == 1 && s[i] != 'c') {
      cout << "NO" << endl;
      return 0;
    }
    if (a == 4 && b == 0 && s[i] != 'n') {
      b = 1;
      while (s[i] != 'n' && i < s.length()) {
        i++;
      }
      i--;
    } else if (a == 4 && s[i] == 'n') {
      a++;
    } else if (a == 4 && b == 1 && s[i] != 'n') {
      cout << "NO" << endl;
      return 0;
    }
    if (a == 3 && b == 0 && s[i] != 'e') {
      b = 1;
      while (s[i] != 'e' && i < s.length()) {
        i++;
      }
      i--;
    } else if (a == 3 && s[i] == 'e') {
      a++;
    } else if (a == 3 && b == 1 && s[i] != 'e') {
      cout << "NO" << endl;
      return 0;
    }
    if (a == 2 && b == 0 && s[i] != 'y') {
      b = 1;
      while (s[i] != 'y' && i < s.length()) {
        i++;
      }
      i--;
    } else if (a == 2 && s[i] == 'y') {
      a++;
    } else if (a == 2 && b == 1 && s[i] != 'y') {
      cout << "NO" << endl;
      return 0;
    }
    if (a == 1 && b == 0 && s[i] != 'e') {
      b = 1;
      while (s[i] != 'e' && i < s.length()) {
        i++;
      }
      i--;
    } else if (a == 1 && s[i] == 'e') {
      a++;
    } else if (a == 1 && b == 1 && s[i] != 'e') {
      cout << "NO" << endl;
      return 0;
    }
    if (a == 0 && b == 0 && s[i] != 'k') {
      b = 1;
      while (s[i] != 'k' && i < s.length()) {
        i++;
      }
      i--;
    } else if (a == 0 && s[i] == 'k') {
      a++;
    } else if (a == 0 && b == 1 && s[i] != 'k') {
      cout << "NO" << endl;
      return 0;
    }
  }
  if (a == 7) {
    cout << "YES" << endl;
  } else {
    cout << "NO" << endl;
  }
  return 0;
  cout << ans << endl;
  return 0;
}
