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)

/* -> Written by <-
   -----------
  |K_A_Z_A_M_A|
  |___________|
  |    ___    |
  |   (^_^)   |
  |  /( | )\  |
  |____|_|____|
    H O A N G
*/

// i hope i get better

// Task name:
#define Task ""
using namespace std;

// Include
#include <bits/stdc++.h>
#include <iostream>
#include <vector>
#include <algorithm>
#include <cstring>
#include <iomanip>
#include <string>
#include <sstream>
#include <cstdio>
#include <vector>
#include <set>
#include <queue>
#include <map>
#include <unordered_map>
#include <stack>

// Define
#define reset(x, value) memset((x), (value) ,sizeof((x)))
#define fr(i,a,b) for(int i = (a); i <= (b); i++)
#define FR(i,a,b) for(int i = (a); i < (b); i++)
#define frr(i,a,b) for(int i = (a); i >= (b); i--)
#define F first
#define S second
#define pb push_back
#define mp make_pair
#define nl "\n"
#define bit(x,i) (x >> i) & 1
#define all(x) (x).begin(), (x).end()
#define optimize(x) (x).resize(unique(all(x)) - (x).begin())
#define Inpf freopen(Task".inp","r",stdin)
#define Outf freopen(Task".out","w",stdout)
#define fasterIO ios_base::sync_with_stdio(false);cin.tie(NULL);cout.tie(NULL);

// typedef
typedef long long ll;
typedef double db;
typedef long double ldb;
typedef pair<int,int> pii;
typedef pair<ll,ll> pll;
typedef vector<int> vii;
typedef vector<ll> vll;

const int base = 131;
const int MOD = 1e9 + 7;
const ll MM = 1ll * MOD * MOD;
const int inf = 0x3f3f3f3f;
const ll INF = 0x3f3f3f3f3f3f3f3f;

void AddMOD(int &x, int y)
{
    x += y;
    if (x >= MOD)
        x -= MOD;
}
int Gcd(int x, int y)
{
    if (y == 0)
        return x;
    return Gcd(y, x % y);
}
template <class T> inline void Gmax(T &x,T y)
{
    x = max((x), (y));
}
template <class T> inline void Gmin(T &x,T y)
{
    x = min((x), (y));
}

void exit_with_runtime()
{
    db x = 1.0 * clock() / CLOCKS_PER_SEC;
    cerr << "\n\n---------------------\nTime elapsed: " << x << " s.\n\n";
    if (x > 1)
        cerr << "TIME LIMIT EXCEEDED!\n\n";
    exit(0);
}

// --------------------------------------------------------------------
const int maxn = 150005;
// --------------------------------------------------------------------

void Solve()
{
    string s;
    cin >> s;
    if (s[1] == 'B') s[1] = 'R';
    else s[1] = 'B';
    cout << s;
}

int main()
{
#ifndef ONLINE_JUDGE
    Inpf;
    Outf;
#endif // ONLINE_JUDGE
    fasterIO;
    int test = 1;
//    cin >> test;
    while (test --)
        Solve();

    // Did you check with the special test case n = 0, n = 1??
    exit_with_runtime();
}

// Goodbye, see u again