Elementary!

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

inputFormat

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.

outputFormat

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

样例

DOCTOR

NO