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)


import heapq
from collections import defaultdict, deque
from math import ceil, factorial, gcd
from itertools import accumulate, permutations
import sys
import bisect


sys.setrecursionlimit(10 ** 7)
INF = float("inf")
MOD = 10 ** 9 + 7

si = lambda: input().strip()
ii = lambda: int(input())
mii = lambda: map(int, input().split())
msi = lambda: map(str, input().split())
lmii = lambda: list(map(int, input().split()))
lmsi = lambda: list(map(str, input().split()))
smii = lambda: sorted(map(int, input().split()))

# ----------

S = si()

if S == "ABC":
    print('ARC')
else:
    print('ABC')