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

Input: Consider Input: Problem: a is half good a work man as b and together they finish a job in 14 days . in how many days working alone b finish the job ?

Output: 21


Input: Consider Input: Problem: a person was asked to subtract 25 % of a number from the original but he subtracted 25 from the number . his answer was 25 more than correct one . what was the original number ?

Output: 200


Input: Consider Input: Problem: a rower can row 7 km / h in still water . when the river is running at 2 km / h , it takes the rower 1 hour to row to big rock and back . how many kilometers is it to big rock ?


Output: 3.21