import sys

def sum(x,y):
	result = x + y
	return result

def doesItChange(ref x):
	return  9

def swap(x,y):
	return (y,x)

i = input("enter the first number: ")
j = input("enter the second number: ")

print "\n"
print sum(i,j)

v = 1
v = doesItChange(v)
print v

i = 1
j = 2
(i,j) = swap(i,j)