ll@N,@A[N];
ll mx=-1,res;
rep(s,1<<12){
    ll t=(1<<12)-1-s;
    ll p=0,q=0;
    bool ok = true;
    rep(i,N){
        if((s&A[i])==A[i]) p|=A[i];
        else if((t&A[i])==A[i]) q|=A[i];
        else {
            ok = false;
        }
    }
    if(!ok){
        continue;
    }
    if(mx<p*q){
        mx=p*q;
        res=s;
    }
}
wt(mx);
rep(i,N)wtN((A[i]&res)==A[i] ? "B" : "W");