#include <bits/stdc++.h>
using namespace std;
int ok(char a) {
  string s = "BCDGJOPQRSU";
  for (char y : s)
    if (y == a) return true;
  return false;
}
int solve() {
  string s;
  cin >> s;
  int q = ok(s[0]);
  for (char a : s) {
    if (q != ok(a)) return 0;
  }
  return 1;
}
int main() { cout << (solve() ? "YES" : "NO") << '\n'; }
