what is wrong in the last code

Question

https://code.sololearn.com/cw588i60BQh9/?ref=app

Answer 1

X = 10
X = X + 10
X = X - 5
print (X)

first = 2
second = 3
third = first * second
print (first , second, third )
first = first + second + third
third = second * first
print (first, second , third )

a = 5
b = 10
add = a + b
mul = a * b
sub = a - b
print(add, mul, sub)

age = input("Your age :")
print(f"Your age is: {age}")