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

Ex Input:
Problem: a cycle is bought for rs . 900 and sold for rs . 1080 , find the gain percent ?

Ex Output:
20 %


Ex Input:
Problem: a and b together can complete work in 6 days . a alone starts working and leaves it after working for 4 days completing only half of the work . in how many days it can be completed if the remaining job is undertaken by b ?

Ex Output:
12


Ex Input:
Problem: a number when divided b the sum of 555 and 445 gives two times their difference as quotient and 30 as the remainder . the number is :

Ex Output:

22030