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

Ex Input:
Problem: what is the range of all the roots of | x ^ 2 - 4 | = x ?

Ex Output:
3

Ex Input:
Problem: a reduction of 20 % in the price of oil enables a house wife to obtain 4 kgs more for rs . 600 , what is the reduced price for kg ?

Ex Output:
30

Ex Input:
Problem: 10 friends meet for movie 20 for picnic and 5 for games 4 for movie & picnic 2 for movie & games , 0 for picnic & games , 2 for all , how many are students are there in all ?

Ex Output:
31