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

Ex Input:
Problem: the population of a bacteria culture doubles every 2 minutes . approximately how many minutes will it take for the population to grow from 1,000 to 300,000 bacteria

Ex Output:
16


Ex Input:
Problem: what decimal fraction is 90 ml of a litre ?

Ex Output:
. 09


Ex Input:
Problem: running at the same constant rate , 6 identical machines can produce a total of 420 bottles per minute . at this rate , how many bottles could 10 such machines produce in 4 minutes ?

Ex Output:

2800