Model Lighting Problem

I am having a problem about lighting of my model.I am pretty new so if you can help i would be glad.When i import this model ;

https://i.hizliresim.com/nJ7YV5.png

It looks like this;

https://i.hizliresim.com/Aym2oz.png

So i think the problem is in blender.Lamp doesnt illuminate the bottom of the model.How can i solve that?Thanks for help…