High School Admission

ZngivaeL is about to take his entrance exam, with four subjects each graded with one of the letters (A), (B), (C) or (D).

There are three types of high schools available: Key High School, Ordinary High School, and Vocational High School, in decreasing order of admission difficulty.

The rules are as follows:
1. If all four subjects are graded at least (C) (i.e. each grade is one of (A, B, C)), then ZngivaeL is eligible to attend Ordinary High School.
2. To be admitted to Key High School, all four subjects must have a grade of either (A) or (B), and at least one subject must be graded (A).
3. If the conditions for Ordinary High School are not met (i.e. at least one subject is graded (D)), then the only option is Vocational High School.

Given the four subject grades, determine the highest difficulty high school that ZngivaeL can attend.

inputFormat

The input consists of a single line containing four space-separated characters, each being one of A, B, C, or D, representing the grades for the four subjects.

outputFormat

Output a single line with one of the following strings, indicating the highest difficulty high school ZngivaeL can attend:
• Key High School
• Ordinary High School
• Vocational High School

sample

A B A B

Key High School