Detailed Instructions: 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.
Q: 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?
A:
127