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<stdlib.h>
#include<string.h>

int main(void)
{
	char str[128] ;
  	char str1[128] = "ABC";
  	char str2[128] = "ARC";
    //printf("文字列を入力してください>");
    scanf("%s",str);
  	if(strcmp(str,str1) == 0)
    	{
          printf("ARC\n");
        }else{
      		if(strcmp(str,str2) == 0){
        		printf("ABC\n");
      		}else{
        		printf("先週開催されたコンテストをABCかARCで入力してください\n");
      		}
       }
	//printf("%s",str);
    return 0;
}