#include <bits/stdc++.h>
using namespace std;
int main() {
  string a;
  int b = 0, d = 0, q = 0, p = 0;
  cin >> a;
  if (a[0] == 'b') b++;
  if (a[0] == 'd') d++;
  if (a[0] == 'q') q++;
  if (a[0] == 'p') p++;
  if (a[1] == 'b') b++;
  if (a[1] == 'd') d++;
  if (a[1] == 'q') q++;
  if (a[1] == 'p') p++;
  if (a[2] == 'b') b++;
  if (a[2] == 'd') d++;
  if (a[2] == 'q') q++;
  if (a[2] == 'p') p++;
  if (a[3] == 'b') b++;
  if (a[3] == 'd') d++;
  if (a[3] == 'q') q++;
  if (a[3] == 'p') p++;
  if (b == 1 && d == 1 && p == 1 && q == 1)
    cout << "Yes" << endl;
  else
    cout << "No" << endl;
  return 0;
}
