stablegradients/pie-gem5-pairs huggingface dataset:
// Slower C++ solution:
#include "bits/stdc++.h"

using namespace std;

#define pb          push_back

#define mp          make_pair

#define ll          long long

#define pii         pair<int, int>

#define vi          vector<int>

#define vii         vector<pii>

#define mi          map<int, int>

#define mii         map<pii, int>

#define all(a)      (a).begin(),(a).end()

#define x           first

#define y           second

#define sz(x)       (int)x.size()

#define endl        '\n'

#define hell        1000000007

#define debug(x) cout << '>' << #x << ':' << x << endl;

#define rep(i,a,b)  for(int i=a;i<b;i++)

#define rev(i,a,b)  for(int i=a;i>=b;i--)

#define lb          lower_bound

#define ub          upper_bound



#define bg(i)       i.begin()

#define fset(it,s)   for(auto it = s.begin(); it != s.end(); it++)

 

#define track(x)                 cerr<<#x<<": "<<x<<endl

#define track2(x, y)             cerr<<#x<<": "<<x<<" | "<<#y<<": "<<y<<endl

#define track3(x, y, z)          cerr<<#x<<":" <<x<<" | "<<#y<<": "<<y<<" | "<<#z<<": "<<z<<endl

#define track4(a, b, c, d)       cerr<<#a<<": "<<a<<" | "<<#b<<": "<<b<<" | "<<#c<<": "<<c<<" | "<<#d<<": "<<d<<endl

 

#define ed(i)       i.end()

#define mem(a)	    memset(a, 0, sizeof(a))



#define MOD         1000000007

int mult(int a,int b, int p=MOD){return ((a%p)*(b%p))%p;}

int add(int a, int b, int p=MOD){return (a + b + p)%p;}

int fpow(int n, int k, int p = MOD) {int r = 1; for (; k; k >>= 1LL) {if (k & 1LL) r = mult(r,n,p); n = mult(n,n,p);} return r;}

int inv(int a, int p = MOD) {return fpow(a, p - 2, p);}

void self_max(int &a, int b) {a = max(a, b); }

void self_min(int &a, int b) {a = min(a, b); }

void self_add(int &a, int b, int p = MOD) { a += b; if(a >= p) a -= p;}

void self_sub(int &a, int b, int p = MOD) { a -= b; if(a < 0) a += p;}

/////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////

 

const int INF = 1e9 + 5;

#define N	    	400001



void solve(){

    string s;

    cin>>s;

    if(s == "ABC")

        cout<<"ARC"<<endl;

    else

        cout<<"ABC"<<endl;



}

int main() {

	ios::sync_with_stdio(false);

	cout<<fixed<<setprecision(20);

	cin.tie(0);

	cout.tie(0);

	int t = 1;

//	cin>>t;

	while(t--){

		solve();

	}

}


// Faster C++ solution for the same problem (measured speedup: 5.439552157340101x):
#include <stdio.h>



int main() {

	char s[10];

	scanf("%s", s);

	

	if (s[1] == 'B') {

		printf ("ARC");

	}

	else {

		printf ("ABC");

	}

	return 0;

}
// Slower C++ solution:
#include<bits/stdc++.h>

using namespace std;

int main()

{

    string s;

    cin>>s;

    if(s=="ABC")cout<<"ARC"<<endl;

    else if(s=="ARC")cout<<"ABC"<<endl;

    return 0;

}

// Faster C++ solution for the same problem (measured speedup: 5.3269965218067465x):
#include <stdio.h>

int main(){

	char contest[10];

	scanf("%s", &contest);

	if (contest[1] == 'B'){

		printf("ARC\n");

	}	else if (contest[1] == 'R'){

		printf("ABC\n");

	}

			

	

	return 0;

}
// Slower C++ solution:
#include<iostream>

using namespace std;

int main(){

     string a;cin>>a;

     if(a=="ABC") cout<<"ARC";

     else cout<<"ABC";

}

// Faster C++ solution for the same problem (measured speedup: 5.314667328610009x):
#include <stdio.h>

int main(){

	char contest[10];

	scanf("%s", &contest);

	if (contest[1] == 'B'){

		printf("ARC\n");

	}	else if (contest[1] == 'R'){

		printf("ABC\n");

	}

			

	

	return 0;

}
// Slower C++ solution:
#include<iostream>

using namespace std;

int main()

{

	string s;

	cin>>s;

	if(s[1]=='B')cout<<"ARC";

	if(s[1]=='R')cout<<"ABC";

}

// Faster C++ solution for the same problem (measured speedup: 5.309677332527836x):
#include <stdio.h>

int main(){

	char contest[10];

	scanf("%s", &contest);

	if (contest[1] == 'B'){

		printf("ARC\n");

	}	else if (contest[1] == 'R'){

		printf("ABC\n");

	}

			

	

	return 0;

}
// Slower C++ solution:
#include<iostream>

#include<cmath>

#include<stack>

#include<vector>

#include<cstring>

#include<algorithm>

#include<set>

#include<queue>

#include <vector>

#include <list>

#include <map>

#include <set>

#include <deque>

#include <stack>

#include <bitset>

#include <algorithm>

#include <functional>

#include <numeric>

#include <utility>

#include <complex>

#include <sstream>

#include <iomanip>

#include <cstdio>

#include <cmath>

#include <cstdlib>

#include <cstring>

#include <ctime>

#include <cassert>

using namespace std;

typedef long long ll;

typedef unsigned long long ull;

const int inf =0x3f3f3f3f;

#define scn(a) scanf("%d",&a)

#define scd(a) scanf("%lf",&a)

#define scl(a) scanf("%lld",&a)

#define ptf(a) printf("%d\n",a)

#define mes(a,b) memset(a,b,sizeof(a))

#define fon(s,n) for(int i=s;i<=n;i++)

#define range(i,a,b) for(int i=a;i<=b;++i)

#define rerange(i,a,b) for(int i=a;i>=b;--i)

#define maxn 1000010

const int S=20;

ll gcd(ll a,ll b) { return b>0 ? gcd(b,a%b):a;}

ll lcm(ll a,ll b){return a*b/gcd(a,b);}

ll q_pow(ll a,ll b,ll mod)

{

	ll ans=1,res=a;

	while(b){

		if(b&1) ans=ans*res%mod;

		res=res*res%mod;

		b>>=1;

	}

	return ans%mod;

}



int month[13]={0,31,28,31,30,31,30,31,31,30,31,30,31};

int main()

{

    string a="ARC",b="ABC";

    string temp;

    cin>>temp;

    if(temp==a) cout<<b<<endl;

    else cout<<a<<endl;



    return 0;

}


// Faster C++ solution for the same problem (measured speedup: 5.321369504948126x):
#include <stdio.h>

int main(){

	char contest[10];

	scanf("%s", &contest);

	if (contest[1] == 'B'){

		printf("ARC\n");

	}	else if (contest[1] == 'R'){

		printf("ABC\n");

	}

			

	

	return 0;

}
// Slower C++ solution:
#include "bits/stdc++.h"

using namespace std;

#define pb          push_back

#define mp          make_pair

#define ll          long long

#define pii         pair<int, int>

#define vi          vector<int>

#define vii         vector<pii>

#define mi          map<int, int>

#define mii         map<pii, int>

#define all(a)      (a).begin(),(a).end()

#define x           first

#define y           second

#define sz(x)       (int)x.size()

#define endl        '\n'

#define hell        1000000007

#define debug(x) cout << '>' << #x << ':' << x << endl;

#define rep(i,a,b)  for(int i=a;i<b;i++)

#define rev(i,a,b)  for(int i=a;i>=b;i--)

#define lb          lower_bound

#define ub          upper_bound



#define bg(i)       i.begin()

#define fset(it,s)   for(auto it = s.begin(); it != s.end(); it++)

 

#define track(x)                 cerr<<#x<<": "<<x<<endl

#define track2(x, y)             cerr<<#x<<": "<<x<<" | "<<#y<<": "<<y<<endl

#define track3(x, y, z)          cerr<<#x<<":" <<x<<" | "<<#y<<": "<<y<<" | "<<#z<<": "<<z<<endl

#define track4(a, b, c, d)       cerr<<#a<<": "<<a<<" | "<<#b<<": "<<b<<" | "<<#c<<": "<<c<<" | "<<#d<<": "<<d<<endl

 

#define ed(i)       i.end()

#define mem(a)	    memset(a, 0, sizeof(a))



#define MOD         1000000007

int mult(int a,int b, int p=MOD){return ((a%p)*(b%p))%p;}

int add(int a, int b, int p=MOD){return (a + b + p)%p;}

int fpow(int n, int k, int p = MOD) {int r = 1; for (; k; k >>= 1LL) {if (k & 1LL) r = mult(r,n,p); n = mult(n,n,p);} return r;}

int inv(int a, int p = MOD) {return fpow(a, p - 2, p);}

void self_max(int &a, int b) {a = max(a, b); }

void self_min(int &a, int b) {a = min(a, b); }

void self_add(int &a, int b, int p = MOD) { a += b; if(a >= p) a -= p;}

void self_sub(int &a, int b, int p = MOD) { a -= b; if(a < 0) a += p;}

/////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////

 

const int INF = 1e9 + 5;

#define N	    	400001



void solve(){

    string s;

    cin>>s;

    if(s == "ABC")

        cout<<"ARC"<<endl;

    else

        cout<<"ABC"<<endl;



}

int main() {

	ios::sync_with_stdio(false);

	cout<<fixed<<setprecision(20);

	cin.tie(0);

	cout.tie(0);

	int t = 1;

//	cin>>t;

	while(t--){

		solve();

	}

}


// Faster C++ solution for the same problem (measured speedup: 5.439381342169878x):
#include <stdio.h>

int main(){

	char contest[10];

	scanf("%s", &contest);

	if (contest[1] == 'B'){

		printf("ARC\n");

	}	else if (contest[1] == 'R'){

		printf("ABC\n");

	}

			

	

	return 0;

}
// Slower C++ solution:
#include<bits/stdc++.h>

using namespace std;

int main()

{

    string s;

    cin>>s;

    if(s=="ABC")cout<<"ARC"<<endl;

    else if(s=="ARC")cout<<"ABC"<<endl;

    return 0;

}

// Faster C++ solution for the same problem (measured speedup: 5.334974196466279x):
#include <stdio.h>



int main(){

	char S [5];

	scanf("%s", &S);

	switch (S[1]) {

		case 'R':

			printf("ABC\n", S);

			break;

		case 'B':

			printf("ARC\n", S);

			break;

	}

	

	return 0;

}
// Slower C++ solution:
#include<iostream>

using namespace std;

int main(){

     string a;cin>>a;

     if(a=="ABC") cout<<"ARC";

     else cout<<"ABC";

}

// Faster C++ solution for the same problem (measured speedup: 5.3226265391515835x):
#include <stdio.h>



int main(){

	char S [5];

	scanf("%s", &S);

	switch (S[1]) {

		case 'R':

			printf("ABC\n", S);

			break;

		case 'B':

			printf("ARC\n", S);

			break;

	}

	

	return 0;

}
// Slower C++ solution:
#include<iostream>

using namespace std;

int main()

{

	string s;

	cin>>s;

	if(s[1]=='B')cout<<"ARC";

	if(s[1]=='R')cout<<"ABC";

}

// Faster C++ solution for the same problem (measured speedup: 5.317629070084374x):
#include <stdio.h>



int main(){

	char S [5];

	scanf("%s", &S);

	switch (S[1]) {

		case 'R':

			printf("ABC\n", S);

			break;

		case 'B':

			printf("ARC\n", S);

			break;

	}

	

	return 0;

}
// Slower C++ solution:
#include<iostream>

#include<cmath>

#include<stack>

#include<vector>

#include<cstring>

#include<algorithm>

#include<set>

#include<queue>

#include <vector>

#include <list>

#include <map>

#include <set>

#include <deque>

#include <stack>

#include <bitset>

#include <algorithm>

#include <functional>

#include <numeric>

#include <utility>

#include <complex>

#include <sstream>

#include <iomanip>

#include <cstdio>

#include <cmath>

#include <cstdlib>

#include <cstring>

#include <ctime>

#include <cassert>

using namespace std;

typedef long long ll;

typedef unsigned long long ull;

const int inf =0x3f3f3f3f;

#define scn(a) scanf("%d",&a)

#define scd(a) scanf("%lf",&a)

#define scl(a) scanf("%lld",&a)

#define ptf(a) printf("%d\n",a)

#define mes(a,b) memset(a,b,sizeof(a))

#define fon(s,n) for(int i=s;i<=n;i++)

#define range(i,a,b) for(int i=a;i<=b;++i)

#define rerange(i,a,b) for(int i=a;i>=b;--i)

#define maxn 1000010

const int S=20;

ll gcd(ll a,ll b) { return b>0 ? gcd(b,a%b):a;}

ll lcm(ll a,ll b){return a*b/gcd(a,b);}

ll q_pow(ll a,ll b,ll mod)

{

	ll ans=1,res=a;

	while(b){

		if(b&1) ans=ans*res%mod;

		res=res*res%mod;

		b>>=1;

	}

	return ans%mod;

}



int month[13]={0,31,28,31,30,31,30,31,31,30,31,30,31};

int main()

{

    string a="ARC",b="ABC";

    string temp;

    cin>>temp;

    if(temp==a) cout<<b<<endl;

    else cout<<a<<endl;



    return 0;

}


// Faster C++ solution for the same problem (measured speedup: 5.329338752624532x):
#include <stdio.h>



int main(){

	char S [5];

	scanf("%s", &S);

	switch (S[1]) {

		case 'R':

			printf("ABC\n", S);

			break;

		case 'B':

			printf("ARC\n", S);

			break;

	}

	

	return 0;

}
// Slower C++ solution:
#include "bits/stdc++.h"

using namespace std;

#define pb          push_back

#define mp          make_pair

#define ll          long long

#define pii         pair<int, int>

#define vi          vector<int>

#define vii         vector<pii>

#define mi          map<int, int>

#define mii         map<pii, int>

#define all(a)      (a).begin(),(a).end()

#define x           first

#define y           second

#define sz(x)       (int)x.size()

#define endl        '\n'

#define hell        1000000007

#define debug(x) cout << '>' << #x << ':' << x << endl;

#define rep(i,a,b)  for(int i=a;i<b;i++)

#define rev(i,a,b)  for(int i=a;i>=b;i--)

#define lb          lower_bound

#define ub          upper_bound



#define bg(i)       i.begin()

#define fset(it,s)   for(auto it = s.begin(); it != s.end(); it++)

 

#define track(x)                 cerr<<#x<<": "<<x<<endl

#define track2(x, y)             cerr<<#x<<": "<<x<<" | "<<#y<<": "<<y<<endl

#define track3(x, y, z)          cerr<<#x<<":" <<x<<" | "<<#y<<": "<<y<<" | "<<#z<<": "<<z<<endl

#define track4(a, b, c, d)       cerr<<#a<<": "<<a<<" | "<<#b<<": "<<b<<" | "<<#c<<": "<<c<<" | "<<#d<<": "<<d<<endl

 

#define ed(i)       i.end()

#define mem(a)	    memset(a, 0, sizeof(a))



#define MOD         1000000007

int mult(int a,int b, int p=MOD){return ((a%p)*(b%p))%p;}

int add(int a, int b, int p=MOD){return (a + b + p)%p;}

int fpow(int n, int k, int p = MOD) {int r = 1; for (; k; k >>= 1LL) {if (k & 1LL) r = mult(r,n,p); n = mult(n,n,p);} return r;}

int inv(int a, int p = MOD) {return fpow(a, p - 2, p);}

void self_max(int &a, int b) {a = max(a, b); }

void self_min(int &a, int b) {a = min(a, b); }

void self_add(int &a, int b, int p = MOD) { a += b; if(a >= p) a -= p;}

void self_sub(int &a, int b, int p = MOD) { a -= b; if(a < 0) a += p;}

/////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////

 

const int INF = 1e9 + 5;

#define N	    	400001



void solve(){

    string s;

    cin>>s;

    if(s == "ABC")

        cout<<"ARC"<<endl;

    else

        cout<<"ABC"<<endl;



}

int main() {

	ios::sync_with_stdio(false);

	cout<<fixed<<setprecision(20);

	cin.tie(0);

	cout.tie(0);

	int t = 1;

//	cin>>t;

	while(t--){

		solve();

	}

}


// Faster C++ solution for the same problem (measured speedup: 5.44752732359099x):
#include <stdio.h>



int main(){

	char S [5];

	scanf("%s", &S);

	switch (S[1]) {

		case 'R':

			printf("ABC\n", S);

			break;

		case 'B':

			printf("ARC\n", S);

			break;

	}

	

	return 0;

}
// Slower C++ solution:
#include<bits/stdc++.h>

using namespace std;

int main()

{

    string s;

    cin>>s;

    if(s=="ABC")cout<<"ARC"<<endl;

    else if(s=="ARC")cout<<"ABC"<<endl;

    return 0;

}

// Faster C++ solution for the same problem (measured speedup: 5.335389689165266x):
#include <stdio.h>



int main() {



    char x[255];

    

    scanf("%s", x);

    if(x[1] == 'B') {

        printf("ARC\n");

    } else {

        printf("ABC\n");

    }



    return 0;

}
// Slower C++ solution:
#include<iostream>

using namespace std;

int main(){

     string a;cin>>a;

     if(a=="ABC") cout<<"ARC";

     else cout<<"ABC";

}

// Faster C++ solution for the same problem (measured speedup: 5.323041070203659x):
#include <stdio.h>



int main() {



    char x[255];

    

    scanf("%s", x);

    if(x[1] == 'B') {

        printf("ARC\n");

    } else {

        printf("ABC\n");

    }



    return 0;

}
// Slower C++ solution:
#include<iostream>

using namespace std;

int main()

{

	string s;

	cin>>s;

	if(s[1]=='B')cout<<"ARC";

	if(s[1]=='R')cout<<"ABC";

}

// Faster C++ solution for the same problem (measured speedup: 5.318043211928961x):
#include <stdio.h>



int main() {



    char x[255];

    

    scanf("%s", x);

    if(x[1] == 'B') {

        printf("ARC\n");

    } else {

        printf("ABC\n");

    }



    return 0;

}
// Slower C++ solution:
#include<iostream>

#include<cmath>

#include<stack>

#include<vector>

#include<cstring>

#include<algorithm>

#include<set>

#include<queue>

#include <vector>

#include <list>

#include <map>

#include <set>

#include <deque>

#include <stack>

#include <bitset>

#include <algorithm>

#include <functional>

#include <numeric>

#include <utility>

#include <complex>

#include <sstream>

#include <iomanip>

#include <cstdio>

#include <cmath>

#include <cstdlib>

#include <cstring>

#include <ctime>

#include <cassert>

using namespace std;

typedef long long ll;

typedef unsigned long long ull;

const int inf =0x3f3f3f3f;

#define scn(a) scanf("%d",&a)

#define scd(a) scanf("%lf",&a)

#define scl(a) scanf("%lld",&a)

#define ptf(a) printf("%d\n",a)

#define mes(a,b) memset(a,b,sizeof(a))

#define fon(s,n) for(int i=s;i<=n;i++)

#define range(i,a,b) for(int i=a;i<=b;++i)

#define rerange(i,a,b) for(int i=a;i>=b;--i)

#define maxn 1000010

const int S=20;

ll gcd(ll a,ll b) { return b>0 ? gcd(b,a%b):a;}

ll lcm(ll a,ll b){return a*b/gcd(a,b);}

ll q_pow(ll a,ll b,ll mod)

{

	ll ans=1,res=a;

	while(b){

		if(b&1) ans=ans*res%mod;

		res=res*res%mod;

		b>>=1;

	}

	return ans%mod;

}



int month[13]={0,31,28,31,30,31,30,31,31,30,31,30,31};

int main()

{

    string a="ARC",b="ABC";

    string temp;

    cin>>temp;

    if(temp==a) cout<<b<<endl;

    else cout<<a<<endl;



    return 0;

}


// Faster C++ solution for the same problem (measured speedup: 5.329753806429968x):
#include <stdio.h>



int main() {



    char x[255];

    

    scanf("%s", x);

    if(x[1] == 'B') {

        printf("ARC\n");

    } else {

        printf("ABC\n");

    }



    return 0;

}
// Slower C++ solution:
#include "bits/stdc++.h"

using namespace std;

#define pb          push_back

#define mp          make_pair

#define ll          long long

#define pii         pair<int, int>

#define vi          vector<int>

#define vii         vector<pii>

#define mi          map<int, int>

#define mii         map<pii, int>

#define all(a)      (a).begin(),(a).end()

#define x           first

#define y           second

#define sz(x)       (int)x.size()

#define endl        '\n'

#define hell        1000000007

#define debug(x) cout << '>' << #x << ':' << x << endl;

#define rep(i,a,b)  for(int i=a;i<b;i++)

#define rev(i,a,b)  for(int i=a;i>=b;i--)

#define lb          lower_bound

#define ub          upper_bound



#define bg(i)       i.begin()

#define fset(it,s)   for(auto it = s.begin(); it != s.end(); it++)

 

#define track(x)                 cerr<<#x<<": "<<x<<endl

#define track2(x, y)             cerr<<#x<<": "<<x<<" | "<<#y<<": "<<y<<endl

#define track3(x, y, z)          cerr<<#x<<":" <<x<<" | "<<#y<<": "<<y<<" | "<<#z<<": "<<z<<endl

#define track4(a, b, c, d)       cerr<<#a<<": "<<a<<" | "<<#b<<": "<<b<<" | "<<#c<<": "<<c<<" | "<<#d<<": "<<d<<endl

 

#define ed(i)       i.end()

#define mem(a)	    memset(a, 0, sizeof(a))



#define MOD         1000000007

int mult(int a,int b, int p=MOD){return ((a%p)*(b%p))%p;}

int add(int a, int b, int p=MOD){return (a + b + p)%p;}

int fpow(int n, int k, int p = MOD) {int r = 1; for (; k; k >>= 1LL) {if (k & 1LL) r = mult(r,n,p); n = mult(n,n,p);} return r;}

int inv(int a, int p = MOD) {return fpow(a, p - 2, p);}

void self_max(int &a, int b) {a = max(a, b); }

void self_min(int &a, int b) {a = min(a, b); }

void self_add(int &a, int b, int p = MOD) { a += b; if(a >= p) a -= p;}

void self_sub(int &a, int b, int p = MOD) { a -= b; if(a < 0) a += p;}

/////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////

 

const int INF = 1e9 + 5;

#define N	    	400001



void solve(){

    string s;

    cin>>s;

    if(s == "ABC")

        cout<<"ARC"<<endl;

    else

        cout<<"ABC"<<endl;



}

int main() {

	ios::sync_with_stdio(false);

	cout<<fixed<<setprecision(20);

	cin.tie(0);

	cout.tie(0);

	int t = 1;

//	cin>>t;

	while(t--){

		solve();

	}

}


// Faster C++ solution for the same problem (measured speedup: 5.447951582031075x):
#include <stdio.h>



int main() {



    char x[255];

    

    scanf("%s", x);

    if(x[1] == 'B') {

        printf("ARC\n");

    } else {

        printf("ABC\n");

    }



    return 0;

}
// Slower C++ solution:
#include<bits/stdc++.h>

using namespace std;

int main()

{

    string s;

    cin>>s;

    if(s=="ABC")cout<<"ARC"<<endl;

    else if(s=="ARC")cout<<"ABC"<<endl;

    return 0;

}

// Faster C++ solution for the same problem (measured speedup: 5.297134011788708x):
#include <stdio.h>



int main() {

	char a[4];

	

	scanf("%s", &a);

	

	if (a[1] == 'R') {

		a[1] = 'B';

		printf("%s\n", a);

		return 0;

	}

	if(a[1] == 'B') {

		a[1] = 'R';

		printf("%s\n", a);

	}

	return 0;

}
// Slower C++ solution:
#include<iostream>

using namespace std;

int main(){

     string a;cin>>a;

     if(a=="ABC") cout<<"ARC";

     else cout<<"ABC";

}

// Faster C++ solution for the same problem (measured speedup: 5.284873934585165x):
#include <stdio.h>



int main() {

	char a[4];

	

	scanf("%s", &a);

	

	if (a[1] == 'R') {

		a[1] = 'B';

		printf("%s\n", a);

		return 0;

	}

	if(a[1] == 'B') {

		a[1] = 'R';

		printf("%s\n", a);

	}

	return 0;

}
// Slower C++ solution:
#include<iostream>

using namespace std;

int main()

{

	string s;

	cin>>s;

	if(s[1]=='B')cout<<"ARC";

	if(s[1]=='R')cout<<"ABC";

}

// Faster C++ solution for the same problem (measured speedup: 5.279911911828558x):
#include <stdio.h>



int main() {

	char a[4];

	

	scanf("%s", &a);

	

	if (a[1] == 'R') {

		a[1] = 'B';

		printf("%s\n", a);

		return 0;

	}

	if(a[1] == 'B') {

		a[1] = 'R';

		printf("%s\n", a);

	}

	return 0;

}
// Slower C++ solution:
#include<iostream>

#include<cmath>

#include<stack>

#include<vector>

#include<cstring>

#include<algorithm>

#include<set>

#include<queue>

#include <vector>

#include <list>

#include <map>

#include <set>

#include <deque>

#include <stack>

#include <bitset>

#include <algorithm>

#include <functional>

#include <numeric>

#include <utility>

#include <complex>

#include <sstream>

#include <iomanip>

#include <cstdio>

#include <cmath>

#include <cstdlib>

#include <cstring>

#include <ctime>

#include <cassert>

using namespace std;

typedef long long ll;

typedef unsigned long long ull;

const int inf =0x3f3f3f3f;

#define scn(a) scanf("%d",&a)

#define scd(a) scanf("%lf",&a)

#define scl(a) scanf("%lld",&a)

#define ptf(a) printf("%d\n",a)

#define mes(a,b) memset(a,b,sizeof(a))

#define fon(s,n) for(int i=s;i<=n;i++)

#define range(i,a,b) for(int i=a;i<=b;++i)

#define rerange(i,a,b) for(int i=a;i>=b;--i)

#define maxn 1000010

const int S=20;

ll gcd(ll a,ll b) { return b>0 ? gcd(b,a%b):a;}

ll lcm(ll a,ll b){return a*b/gcd(a,b);}

ll q_pow(ll a,ll b,ll mod)

{

	ll ans=1,res=a;

	while(b){

		if(b&1) ans=ans*res%mod;

		res=res*res%mod;

		b>>=1;

	}

	return ans%mod;

}



int month[13]={0,31,28,31,30,31,30,31,31,30,31,30,31};

int main()

{

    string a="ARC",b="ABC";

    string temp;

    cin>>temp;

    if(temp==a) cout<<b<<endl;

    else cout<<a<<endl;



    return 0;

}


// Faster C++ solution for the same problem (measured speedup: 5.291538539318491x):
#include <stdio.h>



int main() {

	char a[4];

	

	scanf("%s", &a);

	

	if (a[1] == 'R') {

		a[1] = 'B';

		printf("%s\n", a);

		return 0;

	}

	if(a[1] == 'B') {

		a[1] = 'R';

		printf("%s\n", a);

	}

	return 0;

}