#include<stdio.h>
int main()
{
	int x;
	scanf("%d",&x);
	if(x>1200)
	{
		printf("ARC\n");
//		printf("Smeke's current rating is not less than 1200, thus the output should be ARC.\n");
	}
	else
	{
		printf("ABC\n");
//		printf("Smeke's current rating is less than 1200, thus the output should be ABC.\n");
	}
}