score = 0

    timer = time.clock()

    lives = 3

​

    while timer < 60 and lives > 0:

        if score >= 25:

            x = random.randint(-100,100)

            y = random.randint(-100,100)

            answer = int(raw_input("What is %d + %d? " % (x,y)))

            if answer == x + y:

                print "Correct!"

                score += 1

            else:

                print "Wrong!"

                lives -= 1

        elif score >= 20:

            x = random.randint(-75,75)

            y = random.randint(-75,75)

            answer = int(raw_input("What is %d + %d? " % (x,y)))

            if answer == x + y:

                print "Correct!"

                score += 1

            else:

                print "Wrong!"

                lives -= 1

        elif score >= 15:

            x = random.randint(-50,50)

            y = random.randint(-50,50)

            answer = int(raw_input("What is %d + %d? " % (x,y)))

            if answer == x + y:

                print "Correct!"

                score += 1

            else:

                print "Wrong!"

                lives -= 1

        elif score >= 10:

            x = random.randint(-25,25)

            y = random.randint(-25,25)

            answer = int(raw_input("What is %d + %d? " % (x,y)))

            if answer == x + y:

                print "Correct!"

                score += 1

            else:

                print "Wrong!"

                lives -= 1

        elif score >= 5:

            x = random.randint(-10,10)

            y = random.randint(-10,10)

            answer = int(raw_input("What is %d + %d? " % (x,y)))

            if answer == x + y:

                print "Correct!"

                score += 1

            else:

                print "Wrong!"

                lives -= 1

        elif score >= 0:

            x = random.randint(-5,5)

            y = random.randint(-5,5)

            answer = int(raw_input("What is %d + %d? " % (x,y)))

            if answer == x + y:

                print "Correct!"

                score += 1

            else:

                print "Wrong!"

                lives -= 1

    if lives == 0:

        print "Oh no! You ran out of lives! Your score was %d." % score

    elif timer == 60:

        print "Time's up! Your score is %d." % score

else:

    print "Goodbye!"