#include <bits/stdc++.h>
using namespace std;
int main() {
  ios::sync_with_stdio(0);
  cin.tie(0);
  string s;
  cin >> s;
  map<char, int> M;
  M['A'] = 1;
  M['B'] = 0;
  M['C'] = 0;
  M['D'] = 0;
  M['E'] = 1;
  M['F'] = 1;
  M['G'] = 0;
  M['H'] = 1;
  M['I'] = 1;
  M['J'] = 0;
  M['K'] = 1;
  M['L'] = 1;
  M['M'] = 1;
  M['N'] = 1;
  M['O'] = 0;
  M['P'] = 0;
  M['Q'] = 0;
  M['R'] = 0;
  M['S'] = 0;
  M['T'] = 1;
  M['U'] = 0;
  M['V'] = 1;
  M['W'] = 1;
  M['X'] = 1;
  M['Y'] = 1;
  M['Z'] = 1;
  int ans = 0;
  for (auto i : s) ans += M[i];
  if (ans == s.size() || ans == 0)
    cout << "YES" << '\n';
  else
    cout << "NO" << '\n';
  return 0;
}
