#include <bits/stdc++.h>
int flag;
std::string buffer;
int main() {
  std::cin >> buffer;
  for (std::string::size_type i = 0; i < buffer.size(); ++i)
    switch (buffer[i]) {
      case 'B':
      case 'C':
      case 'D':
      case 'G':
      case 'J':
      case 'O':
      case 'P':
      case 'Q':
      case 'R':
      case 'S':
      case 'U':
        flag |= 1;
        break;
      default:
        flag |= 2;
        break;
    }
  std::cout << ((flag & 3) == 3 ? "NO" : "YES");
}
