02. Add and Subtract

def result():
    first_num = int(input())
    second_num = int(input())
    third_num = int(input())

    def add():
        return first_num + second_num

    def subtract():
        return add() - third_num

    return subtract()


print(result())


Или:)

def result():
    return int(input()) + int(input()) - int(input())

print(result())