#include <bits/stdc++.h>
using namespace std;
signed main() {
  string s;
  cin >> s;
  string a = "keyofscience";
  long long e = s.size();
  long long b = 0;
  long long cnt = 0;
  if (s == a) {
    cout << "YES" << endl;
  } else {
    for (long long i = 0; i < e; i++) {
      if (s.at(i) == a.at(b)) {
        b++;
        cnt++;
      }
    }
    if (cnt == a.size()) {
      cout << "YES" << endl;
    } else {
      cout << "NO" << endl;
    }
  }
}
