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 C (GCC 9.2.1) (judge verdict: Accepted)

#include <stdio.h>
#include <string.h>

int main(void)
{
    char contest[4];

    fgets(contest, 4, stdin);
    contest[strcspn(contest, "\n")] = '\0';

    if (strcmp(contest, "ABC") == 0)
        puts("ARC");
    if (strcmp(contest, "ARC") == 0)
        puts("ABC");

    return 0;
}