Problem:
Score : 100 points

Problem Statement

AtCoder Inc. holds a contest every Saturday.

There are two types of contests called ABC and ARC, and just one of them is held at a time.

The company holds these two types of contests alternately: an ARC follows an ABC and vice versa.

Given a string S representing the type of the contest held last week, print the string representing the type of the contest held this week.

Constraints

S is ABC or ARC.

Input

Input is given from Standard Input in the following format:

S

Output

Print the string representing the type of the contest held this week.

Sample Input 1

ABC

Sample Output 1

ARC

They held an ABC last week, so they will hold an ARC this week.

Solution in Python (3.8.2) (judge verdict: Runtime Error)

N,M=map(int,input().split())
high_list=list(map(int,input().split()))
pathlist=[]
for i in range(M):
    pathlist.append(list(map(int,input().split())))
waylist=[0]*N
ans=0
#i行目にi番目から行ける展望台をすべて入れる
for n in range(1,N+1):
    for m in pathlist:
        if(n in m):#もし経路に入っていたら
            if(m[0]==n):#自身じゃない方の高さを代入
                if(high_list[n-1]>high_list[m[1]-1]):
                    ans=ans+1
            else:
                if(high_list[n-1]>high_list[m[0]-1]):
                    ans=ans+1
print(ans)