#include <bits/stdc++.h>
using namespace std;
int main() {
  int arr[] = {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};
  string s;
  cin >> s;
  int ans = 0;
  for (char x : s) ans += arr[x - 65];
  if (ans == 0 or ans == s.size())
    cout << "YES\n";
  else
    cout << "NO\n";
  return 0;
}
