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(){
  char line[128];
  char *pre_contest[] = {};
  char *contest[] ={"ABC","ARC"};
  fgets(line,sizeof(line),stdin);
  pre_contest[0] = line;

  if(strncmp(contest[0],pre_contest[0],3)==0){
    printf("%s",contest[1]);
  }
  if(strncmp(contest[1],pre_contest[0],3)==0){
    printf("%s",contest[0]);
  }

  return 0;

}