

Input

The input consists of a single string of uppercase letters A-Z. The length of the string is between 1 and 10 characters, inclusive.

Output

Output "YES" or "NO".

Examples

Input


GENIUS


Output


YES


Input


DOCTOR


Output


NO


Input


IRENE


Output


YES


Input


MARY


Output


NO


Input


SMARTPHONE


Output


NO


Input


REVOLVER


Output


YES


Input


HOLMES


Output


NO


Input


WATSON


Output


YES
import java.util.*;

import java.io.*;

public class Main implements Runnable {

  public static void main(String[] args) {
    new Thread(null, new Main(), "whatever", 1 << 26).start();
  }

  private Scanner sc;
  private StringBuilder sb;

  public void run() {
    sc = new Scanner(System.in);
    // sb=new StringBuilder();
    // int t = sc.nextInt();
    // while (t-- > 0) {
      solve();
    // }
  }

  public void solve() {
      String s=sc.next().toLowerCase();
      if(s.length()<=2){
          System.out.println("YES");
          return;
      }
      int ppch,pch,ch;
      ppch=s.charAt(0)-'a';
      pch=s.charAt(1)-'a';
      for(int i=2;i<s.length();i++){
          ch=s.charAt(i)-'a';
          if(ch==(pch+ppch)%26){
              ppch=pch;
              pch=ch;
          }else{
              System.out.println("NO");
              return;
          }
      }
      System.out.println("YES");
  }

  class FastScanner {
    private BufferedReader reader = null;
    private StringTokenizer tokenizer = null;

    public FastScanner() {
      reader = new BufferedReader(new InputStreamReader(System.in));
      tokenizer = null;
    }

    public String next() {
      if (tokenizer == null || !tokenizer.hasMoreTokens()) {
        try {
          tokenizer = new StringTokenizer(reader.readLine());
        } catch (IOException e) {
          throw new RuntimeException(e);
        }
      }
      return tokenizer.nextToken();
    }

    public String nextLine() {
      if (tokenizer == null || !tokenizer.hasMoreTokens()) {
        try {
          return reader.readLine();
        } catch (IOException e) {
          throw new RuntimeException(e);
        }
      }
      return tokenizer.nextToken("\n");
    }

    public long nextLong() {
      return Long.parseLong(next());
    }

    public int nextInt() {
      return Integer.parseInt(next());
    }

    public double nextDouble() {
      return Double.parseDouble(next());
    }

    public float nextFloat() {
      return Float.parseFloat(next());
    }

    public int[] nextIntArray(int n) {
      int[] a = new int[n];
      for (int i = 0; i < n; i++) {
        a[i] = nextInt();
      }
      return a;
    }

    public String[] nextStringArray(int n) {
      String[] a = new String[n];
      for (int i = 0; i < n; i++) {
        a[i] = next();
      }
      return a;
    }

    public long[] nextLongArray(int n) {
      long[] a = new long[n];
      for (int i = 0; i < n; i++) {
        a[i] = nextLong();
      }
      return a;
    }

  }

}
