Hey, Bucky!!

I am having a problem with global variables. Here is my code:

__author__ = 'MovieMaker'

global c
global f


def beef():
print"This is Beef!"

def f2c():
global c
global f
f = (c * (9/5+32))
print(f)

def c2f():
global c
global f
c = ((f-32) * (5/9))
Print(c)

beef()

f2c()

c2f()

could you please tell me HOW I could define c and f.

Thanks,
Mel