TypeError: Can’t convert ‘int’ object to str implicitly

I am trying to write a text game and I have run into an error in the function I am defining that lets you basically spend your skill points after you make your character. At first, the error stated that I was attempting to subtract a string from an integer in this part of the code:balance - strength. Obviously that was wrong so I fixed it with strength = int(strength)… but now I am getting this error which I have never seen before(new programmer) and I am stumped on what exactly it is trying to tell me and how I fix it.