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: Wrong Answer)

#include<stdio.h>
#include<math.h>
#include<string.h>
#define T 100000
int main(){
    int N,M;
    scanf("%d %d",&N,&M);

    int H[N];
    int i;
    for(i=0;i<N;i++){
        scanf("%d",&H[i]);
    }

    int j;
    int A[M];
    int B[M];
    int flag[N];
    for(i=0;i<N;i++){
        flag[i] = 1;
    }

    for(j=0;j<M;j++){
        scanf("%d %d",&A[j],&B[j]);

        if(H[ (A[j]-1) ] > H[ (B[j]-1) ]) {flag[A[j] -1] =1; flag[B[j] -1] = 0;}
        else{flag[B[j]-1] =1; flag[A[j]-1] = 0;}
    }

    int count=0;
    for(i=0;i<N;i++){
        if(flag[i] == 1){count += 1;}
    }

    printf("%d",count);


return 0;

}