The task is to generate the correct answer for a given math problem.

Ex Input:
Problem: if a = 105 and a ^ 3 = 21 × 25 × 45 × z , what is the value of z ?

Ex Output:
49


Ex Input:
Problem: a , b and c start a business each investing 20,000 . after 5 months a withdrew 5000 , b withdrew 4000 and c invests 6000 more . at the end of the year , a total profit of 69,900 was recorded . find the share of b .

Ex Output:
28,200


Ex Input:
Problem: the area of circle o is added to its diameter . if the circumference of circle o is then subtracted from this total , the result is 4 . what is the area of circle o ?

Ex Output:

4 π'