How to give null value to a variable?

Question

x=int(input())
y=int(input())
try:
z=input()
finally :
userList = [x,y,z]
sum = 0
for num in userList:
a=int(num)
if(a%2 == 0):
sum += int(num)
print(sum)

Answer 1

Z=input()or 0