// parameter "input" gets all data
function Main(input) {
  console.log(input === 'ABC' ? 'ARC' : 'ABC');
  return;
  
	// the first line is assigned to input[0], the second line is assigned to input[1] similarly.
	input = input.split("\n");
	tmp = input[1].split(" ");
	// convert string from integer using "parseInt"
	var a = parseInt(input[0], 10);
	var b = parseInt(tmp[0], 10);
	var c = parseInt(tmp[1], 10);
	var s = input[2];
	//output
	console.log('%d %s',a+b+c,s);
}
// Don't edit this line!
Main(require("fs").readFileSync("/dev/stdin", "utf8"));