Problem Statement

AtCoder currently holds four series of regular contests: ABC, ARC, AGC, and AHC.

What is the series of regular contests currently held by AtCoder in addition to $S_1$, $S_2$, and $S_3$?

Constraints

• Each of $S_1$, $S_2$, and $S_3$ is ABC, ARC, AGC, or AHC.
• $S_1$, $S_2$, and $S_3$ are pairwise different.

Input

Input is given from Standard Input in the following format:

$S_1$ $S_2$ $S_3$

Output

Print the answer.

Sample Input 1

ARC
AGC
AHC

Sample Output 1

ABC

Given in input are ARC, AGC, and AHC. The rest is ABC.

Sample Input 2

AGC
ABC
ARC

Sample Output 2

AHC