What am I doing wrong?

Question

I get either a 'cannot assign to literal' or 'cannot assign to operator' error in this string:
int(cy) - int(UserAge) = 'B'

Sorry if it is silly as a program but I'm just a 14 year-old learning to code.

print('Welcome. This program will tell you which year you were born')
UserAge=input('Please enter your age: ')
print('Your age is')
print (UserAge)
while True:
ansA = input('Do you confirm? ')
y = 'Yes'
n = 'No'
if ansA == y:
print('Thank You!')
if ansA == n:
UserAge=input('Please re-enter your age: ')
else:
UserAge=input('Please enter a valid answer: ')
cy = input('What is the current year?')
print('The current year is')
print(cy)
while True:
ansCY = input('Do you confirm?')
if ansCY == y:
print('Thank you')
if ansCY == n:
cy = input('Please re-enter the current year')
else:
cy = input('Please enter a valid answer')
int(cy) - int(UserAge) = 'B'
print('You were born in')
print(B)
print('Thanks for using this test program!')

Answer 1

Change that line to

B = int(cy) - int(UserAge)

Always put the variable name to be assigned on the left of the =.

Answer 2

B should be an integer but you use it as a character .So instead you can declare B = ....
Here in your code B= int(cy)-int(UserAge).