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

Input: Consider Input: Problem: what is the diagonal of a square field whose perimeter is 64 m ?

Output: 16 √ 2 m


Input: Consider Input: Problem: if a - b = 5 and a 2 + b 2 = 31 , find the value of ab .

Output: 3


Input: Consider Input: Problem: the bankers discount of a certain sum of money is rs . 18 and the true discount on the same sum for the same time is rs . 15 . the sum due is :


Output: 90