You are given a math word problem and you are supposed to only use subtraction on the numbers embedded in the text to answer the following question and then only report the final numerical answer.

Example Input: Context: Winter is almost here and most animals are migrating to warmer countries. 86 bird families flew away for the winter from near a mountain. If there were 45 bird families living near the mountain initially 

 Question: How many more bird families flew away for the winter than those that stayed behind?
Example Output: 127

Example Input: Context: Paul got a box of 521 crayons and 66 erasers for his birthday. At the end of the school year he only had 154 left while not having lost a single erasers. 

 Question: How many crayons had been lost or given away?
Example Output: 367

Example Input: Context: Haley grew 14 trees in her backyard. After a typhoon 9 died. 

 Question: How many more trees died in the typhoon than those that survived?
Example Output:
4