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: Consider Input: andy had 31 baseball cards . his dad gave him some more . then andy had 50 baseball cards . how many baseball cards did andy get from his dad ?

Output: 19

Input: Consider Input: a restaurant has 94 pieces of cutlery . 38 are forks 27 are knives and the rest are spoons . how many spoons are there ?

Output: 29

Input: Consider Input: a number machine changes the value of the numbers placed inside it . my number machine will add 15 to a number and then subtract 6 from the sum . if i put in the number 68 what number will come out of the machine ?
Output: 77