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?

Input

Input is given from Standard Input in the following format:
S_1
S_2
S_3

Output

Print the answer.

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.

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

见题面 Input 部分

见题面 Output 部分