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 PyPy3 (7.3.0) (judge verdict: Accepted)

# python3

#===============================================================================
from collections import defaultdict, Counter
from functools import lru_cache
from heapq import heappush, heappop
from math import gcd, floor, ceil
from sys import stdin, stdout

def ilist():
    return [int(x) for x in stdin.readline().strip().split(" ")]
def iint():
    return int(stdin.readline().strip())
def istr():
    return stdin.readline().strip()
##==============================================================================


def solve():
    pass


if __name__ == '__main__':
    s = istr()
    if s == "ABC":
        print("ARC")
    else:
        print("ABC")