#include <bits/stdc++.h>
using namespace std;
template <typename T>
void LastOut(T D) {
  cout << D << "\n";
  exit(0);
}
const char Neat[100] = {'A', 'E', 'F', 'H', 'I', 'K', 'L', 'M',
                        'N', 'T', 'V', 'W', 'X', 'Y', 'Z'};
bool Flag[100];
int main() {
  ios_base ::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  for (int i = 0; i < 15; i++) Flag[int(Neat[i])] = 1;
  string S;
  cin >> S;
  int Col = 0;
  for (int i = 0; i < S.size(); i++)
    if (Flag[int(S[i])]) Col++;
  if (!Col || !(Col - S.size()))
    cout << "YES\n";
  else
    cout << "NO\n";
  return 0;
}
