Definition: Given a math word problem, answer the following question. You might need to apply addition or subtraction mathematical operators on the numbers embedded in the text to answer the question and then only report the final numerical answer.
Input: thanksgiving came and their family hosted their building 's thanksgiving dinner . they prepared a lot of food so she asked her parents if they could donate some to the soup kitchen next bock . if they prepared 36 turkeys and gave 18 of it to the soup kitchen how many were left for them to eat ?
Output:
18