#include <bits/stdc++.h>
using namespace std;
string c = "BCDGJOPQRSU";
string s = "AEFHIKLMNTVWXYZ";
string i;
int main() {
  int nc = 0, ns = 0;
  cin >> i;
  for (char x : i) {
    bool u = false;
    for (char cx : c) {
      if (x == cx) {
        nc++;
        u = true;
        break;
      }
    }
    if (u) continue;
    for (char sx : s) {
      if (x == sx) {
        ns++;
        break;
      }
    }
  }
  if ((ns && !nc) || (!ns && nc))
    cout << "YES\n";
  else
    cout << "NO\n";
}
