TypeError:无法将'int'对象转换为str隐式错误python

Question

我读了其他的问题,但我试图做的事情是不同的我试图在python中制作一个计算器,并试图将变量输入事物变成一个整数,所以我可以添加它.这是我的代码还没有完成,我是一个初学者:

print("Hello! Whats your name?")
myName = input()
print("What do you want me to do? " + myName)
print("I can add, subtract, multiply and divide.")
option = input('I want you to ')
if option == 'add':
    print('Enter a number.')
    firstNumber = input()
    firstNumber = int(firstNumber)

    print('Enter another number.')
    secondNumber = input()
    secondNumber = int(secondNumber)

    answer = firstNumber + secondNumber

    print('The answer is ' + answer)

它能做什么:

Hello! Whats your name?
Jason
What do you want me to do? Jason
I can add, subtract, multiply and divide.
I want you to add
Enter a number.
1
Enter another number.
1
Traceback (most recent call last):
File "C:/Python33/calculator.py", line 17, in <module>
print('The answer is ' + answer)
TypeError: Can't convert 'int' object to str implicitly 

任何帮助,将不胜感激 :)