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: Accepted)

from collections import defaultdict

import sys
sys.setrecursionlimit(10**6)
ii = lambda: int(input())
mis = lambda: map(int,input().split())
lmis = lambda: list(mis())
INF = float('inf')

def main():
        s=input()
        print('ABC' if s=="ARC" else "ARC")


if __name__ == "__main__":
    main()