Answer:
The output of the document. write statement is 
Step-by-step explanation:
Initially: 
 and 

The iteration is repeated 5 times and the calculation is as follows:
First iteration:
:=> 

:=> 

:=>

Second iteration:
:=> 

:=> 

:=>

Third iteration:
:=> 

:=> 

:=>

Fourth iteration:
:=> 

:=> 

:=>

Fifth iteration:
:=> 

:=> 

:=>

End of iteration
document. write(c) prints the value of c which is 8