#include <bits/stdc++.h>
using namespace std;
string st;
int a[100000] = {1, 0, 0, 0, 1, 1, 0, 1, 1, 0, 1, 1, 1,
                 1, 0, 0, 0, 0, 0, 1, 0, 1, 1, 1, 1, 1};
int main() {
  cin >> st;
  for (int i = 1; i < st.size(); i++)
    if (a[int(st[i] - 'A')] != a[int(st[i - 1] - 'A')]) {
      cout << "NO";
      return 0;
    }
  cout << "YES";
  return 0;
}
