const Main = (input) => {
    ans=''
    const lines = input.split('\n')
    for(i=0;i<lines.length;i++){
        if(lines[i].length===0){
            continue
        }
        line=lines[i].trim().split(" ").map(n=>parseInt(n))
        a=line[0]
        ans+=solve(a)+'\n'
    }
    ans=ans.trim()
    console.log(ans)
    return ans
}

function solve(a){
    if(a=='ABC'){
        return "ARC"
    }else {
        return "ABC"
    }
}

Main(require('fs').readFileSync('/dev/stdin', 'utf8'))