How much RAM i can attach in my laptop?

I have Lenovo Flex 2-14 Laptop
(4th Gen Intel Core i5-
4GB RAM-
500GB HDD+8GB SSD-
14 Inches Touch-
Windows 8.1-
2GB Graphics)
I want to upgrade the RAM from 4 to 12.
Can i directly purchase a 8 GB RAM and attach it.
Or it has special combination.
Tell me What i purchase?
There are two slots. One is empty and another has 4 GB placed inside.

Guest

Capacity of RAM depends upon motherboard in two ways. Number one: Capacity of MB to accept RAM and Second: available RAM slots in Mother board. I don't know about your laptop's Mother board. Better you check your laptop manual about it. But be sure you can't increase RAM unless these two things available in your laptop.

Also check the clock speed before purchase if RAM i.e. Looks like 1333, 1600, 1833 etc
As i think (Not sure) your laptop has two RAM slot having 2x2 GB RAM.

Ashish