Noob In Pine Script

Can you help me to write this code correctly

signal= HLv==HLv1==HLv2==-1 ? sell : buy

if signal == buy

plotshape(Buy,title="Buy", color=green, style=shape.arrowup,location=location.belowbar, text="Buy")

else

plotshape(Sell,title="Sell", color=red, style=shape.arrowdown,text="Sell")