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)

use proconio::*;
#[allow(unused_imports)]
use proconio::marker::{Bytes, Chars};
use std::*;

#[allow(dead_code)]
const MOD: i128 = 100_000_007;

#[fastout]
fn main() {
    input!{
        s : String
    }
    let ans = if s == "ABC" {
        "ARC"
    } else {
        "ABC"
    };
    println!("{}",ans);
}