codeforces#P1331F. Elementary!

Elementary!

Description

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 "YES" or "NO".

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".

Samples

GENIUS
YES
DOCTOR
NO
IRENE
YES
MARY
NO
SMARTPHONE
NO
REVOLVER
YES
HOLMES
NO
WATSON
YES