#include <bits/stdc++.h>
using namespace std;
char a[] = {'A', 'E', 'F', 'H', 'I', 'K', 'L', 'M',
            'N', 'T', 'V', 'W', 'X', 'Y', 'Z'};
int main() {
  string s;
  int num1 = 0, num2 = 0;
  cin >> s;
  for (auto c : s) {
    bool flag = 0;
    for (int i = 0; i <= 14; i++)
      if (c == a[i]) flag = 1;
    if (flag)
      num1++;
    else
      num2++;
  }
  if (num1 == 0 || num2 == 0)
    puts("YES");
  else
    puts("NO");
  return 0;
}
