import java.util.*

private val readListInt: ()->List<Int> = { readLine()!!.split(' ').map(String::toInt) }
private val readString: ()->String = {readLine()!!}

fun main(args: Array<String>) {
    val S = readString()

    if (S == "ABC") {
        println("ARC")
    } else {
        println("ABC")
    }
}
