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)

from sys import stdin
from sys import setrecursionlimit

setrecursionlimit(10 ** 7)

s = stdin.readline().rstrip()

if s == "ABC":
    print("ARC")
else:
    print("ABC")