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: Runtime Error)

#include<stdio.h>
int main()
{
	int n,k,d,a,i,j,cnt,flg[101]={0};
	scanf("%d %d",&n,&k);
	for(i=0;i<k;i++){
		scanf("%d",&d);
		for(j=0;j<d;j++){
			scanf("%d",&a);
			flg[a]=1;
		}
	}
	for(i=1;i<=n;i++){
		if(flg[i]==0){
			cnt++;
		}
	}
	printf("%d\n",cnt);
	return 0;
}