This is the bass line that runs all the way through the song.

The chords used are F# B C#.
 
E||-----------------------------|-----------------------------|
B||-----------------------------|-----------------------------|
G||---------------------1-------|-----------------------------|
D||-----4-4----4------1------1--|-----3-3----3------3-3----3--|
A||---------------2-2-----------|--4------------4-4-----------|
E||--2--------------------------|-----------------------------|
 
The song slows down near the end and Rostam sings. The chords are B F# C#.
            
E||-------------------------------------------------------|
B||------7-------7--------2--------2--------2----------9--|
G||----8-------8-------3--------3--------3---------10-----|
D||--9-------9------4--------4--------4--------11---------|
A||-------------------------------------------------------|
E||-------------------------------------------------------|