#include <bits/stdc++.h>
using namespace std;
int read() {
  int x = 0, f = 1;
  char ch = getchar();
  while (ch < '0' || ch > '9') {
    if (ch == '-') f = -1;
    ch = getchar();
  }
  while (ch <= '9' && ch >= '0')
    x = (x << 1) + (x << 3) + (ch ^ 48), ch = getchar();
  return x * f;
}
int a[30] = {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};
char s[30];
int n, m;
int zhi = 1, qu = 1;
int main() {
  scanf("%s", s);
  int len = strlen(s);
  for (int i = 0; i < len; i++) {
    if (a[s[i] - 'A'] == 1) qu = 0;
    if (a[s[i] - 'A'] == 0) zhi = 0;
  }
  if (qu || zhi)
    cout << "Yes";
  else
    cout << "No";
  return 0;
}
