I am trying to execute the following python code
def attributeSelection():
    balance = 25
    print("Your SP balance is currently 25.")
    strength = input("How much SP do you want to put into strength?")
    strength = int(strength)
    balanceAfterStrength = balance - strength
    if balanceAfterStrength == 0:
        print("Your SP balance is now 0.")
        attributeConfirmation()
    elif strength < 0:
        print("That is an invalid input. Restarting attribute selection. Keep an eye on your balance this time!")
        attributeSelection()
    elif strength > balance:
        print("That is an invalid input. Restarting attribute selection. Keep an eye on your balance this time!")
        attributeSelection()
    elif balanceAfterStrength > 0 and balanceAfterStrength < 26:
        print("Ok. You're balance is now at " + balanceAfterStrength + " skill points.")
    else:
        print("That is an invalid input. Restarting attribute selection.")
        attributeSelection()
And it gives me the following error:
  Your SP balance is currently 25.
How much SP do you want to put into strength?5
Traceback (most recent call last):
  File "C:\Python32\APOCALYPSE GAME LIBRARY\apocalypseGame.py", line 205, in <module>
    gender()
  File "C:\Python32\APOCALYPSE GAME LIBRARY\apocalypseGame.py", line 22, in gender
    customizationMan()
  File "C:\Python32\APOCALYPSE GAME LIBRARY\apocalypseGame.py", line 54, in customizationMan
    characterConfirmation()
  File "C:\Python32\APOCALYPSE GAME LIBRARY\apocalypseGame.py", line 93, in characterConfirmation
    characterConfirmation()
  File "C:\Python32\APOCALYPSE GAME LIBRARY\apocalypseGame.py", line 85, in characterConfirmation
    attributeSelection()
  File "C:\Python32\APOCALYPSE GAME LIBRARY\apocalypseGame.py", line 143, in attributeSelection
    print("Ok. You're balance is now at " + balanceAfterStrength + " skill points.")
TypeError: Can't convert 'int' object to str implicitly
What is the issue?