#include <bits/stdc++.h>
using namespace std;
int main() {
  string a = "QRUOPSDGJBC";
  string b = "AWETYIFHKLMNVXZ";
  vector<int> v(26, 1);
  for (auto c : a) {
    v[c - 'A'] = -1;
  }
  string s;
  cin >> s;
  for (int i = 0; i < s.size(); ++i) {
    if (v[s[i] - 'A'] != v[s[0] - 'A']) {
      cout << "NO\n";
      return 0;
    }
  }
  cout << "YES\n";
  return 0;
}
