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)

import sys
INF = 10**9
sys.setrecursionlimit(INF)


def main():
    s, = open(0).read().split()

    ans = 'ARC' if s == 'ABC' else 'ABC'
    print(ans)
    return(ans)


if __name__ == '__main__':
    main()