input: n(4,1,255),m(13,1,255);drawgbk(c=c,colorrgb(90,90,90),colorrgb(0,0,0),1);aa:=ref(h,n)=hhv(h,2*n+1);aaa:=filter(aa,n);bb:=bkset(aaa,n+1);cc1:=filter(bb,n);cc:=cc1 or islastbar;aa2:=ref(l,n)=llv(l,2*n+1);aaa2:=filter(aa2,n);bb2:=backset(aaa2,n+1);cc22:=filter(bb2,n);cc2:=cc22 and not(cc1);ea:=backset(cc,ref(baast(cc2),1)+1);eb:=ea>ref(ea,1);ee:=backset(eb,2);ff1:=ee>ref(ee,1);ee2:=backset(ff1 and count(cc,ref(barslast(cc2),1)+2)=0,ref(barslast(cc2),1)+2);ff2:=ee2>ref(ee2,1);ee3:=backset(ff2