'''  Purpose:  introduce variable usage, assignment and hand-checking of code.
'''

n = 17
print( "n =", n ) 

s = 2 * n 
print( "s =", s )

t = s + 4
print( "t =", t ) 

u = t // 2
print( "u =", u ) 

v = u - n
print( "v =", v ) # As a general thing, printing doesn't change
# the value of a variable. You have to reassign the
# variable to change the value of a variable.
# Here, v was 2.

u = -5
print( "u =", u ) 

# v = u - n # Reassigning v's value now!
print( "v =", v )
# We print v again and notice nothing changed because
# we didn't reassign v so it's still 2!

#