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 Rust (1.42.0) (judge verdict: Accepted)

// -*- coding:utf-8-unix -*-


use proconio::input;

// ABC086C - Traveling
// https://atcoder.jp/contests/abs/fasks/arc089_a
use itertools::Itertools;

fn main() {
/*     input! {
        n: usize,
        mut plan: [(i32, i32, i32); n],  // Vec<(i32, i32, i32)>
    }
 */
    input! {
        s: String,
    }
    if s == "ABC" {
        println!("ARC");
    } else {
        println!("ABC");
    }
}