#include <stdio.h>
#include <stdlib.h>
#include <math.h>
#include <string.h>
#define Rep(i,a,n)for(int i=(int)(a);i<(int)(n);i++)
#define rep(i,n)Rep(i,0,n)
typedef long long ll;
typedef long double ld;
#define Ma(x,y) ((x)>(y)?(x):(y))
#define mi(x,y) ((x)<(y)?(x):(y))

int main() {
	char c[100];
	scanf("%s", c);
	if (c[1] == 'R')printf("ABC");
	else printf("ARC");
}