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

Ex Input:
Problem: two trains of length 100 meters and 200 meters are 450 meters apart . they are moving towards each other on parallel tracks , at speeds of 90 km / h and 72 km / h . after how many seconds will the trains meet ?

Ex Output:
10


Ex Input:
Problem: how many zeroes are there at the end of the number n , if n = 100 ! + 200 ! ?

Ex Output:
2


Ex Input:
Problem: if x is an integer and 2.134 × 10 ^ x is less than 21,000 , what is the greatest possible value for x ?

Ex Output: