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+--- Day 16: Ticket Translation ---
+
+As you're walking to yet another connecting flight, you realize that one of the legs of your
+re-routed trip coming up is on a high-speed train. However, the train ticket you were given is in a
+language you don't understand. You should probably figure out what it says before you get to the
+train station after the next flight.
+
+Unfortunately, you can't actually read the words on the ticket. You can, however, read
+the numbers, and so you figure out the fields these tickets must have and the
+valid ranges for values in those fields.
+
+You collect the rules for ticket fields, the numbers on your ticket, and
+the numbers on other nearby tickets for the same train service (via the airport
+security cameras) together into a single document you can reference (your puzzle input).
+
+The rules for ticket fields specify a list of fields that exist somewhere
+on the ticket and the valid ranges of values for each field. For example, a rule like
+class: 1-3 or 5-7 means that one of the fields in every ticket is named class and can be any value
+in the ranges 1-3 or 5-7 (inclusive, such that 3 and 5 are both valid in this field, but 4 is not).
+
+Each ticket is represented by a single line of comma-separated values. The values are the numbers on
+the ticket in the order they appear; every ticket has the same format. For example, consider this
+ticket:
+
+.--------------------------------------------------------.
+| ????: 101    ?????: 102   ??????????: 103     ???: 104 |
+|                                                        |
+| ??: 301  ??: 302             ???????: 303      ??????? |
+| ??: 401  ??: 402           ???? ????: 403    ????????? |
+'--------------------------------------------------------'
+
+Here, ? represents text in a language you don't understand. This ticket might be represented as
+101,102,103,104,301,302,303,401,402,403; of course, the actual train tickets you're looking at are
+much more complicated. In any case, you've extracted just the numbers in such a way
+that the first number is always the same specific field, the second number is always a different
+specific field, and so on - you just don't know what each position actually means!
+
+Start by determining which tickets are completely invalid; these are tickets that
+contain values which aren't valid for any field. Ignore your ticket for
+now.
+
+For example, suppose you have the following notes:
+
+class: 1-3 or 5-7
+row: 6-11 or 33-44
+seat: 13-40 or 45-50
+
+your ticket:
+7,1,14
+
+nearby tickets:
+7,3,47
+40,4,50
+55,2,20
+38,6,12
+
+It doesn't matter which position corresponds to which field; you can identify invalid
+nearby tickets by considering only whether tickets contain values that are not
+valid for any field. In this example, the values on the first nearby ticket are all
+valid for at least one field. This is not true of the other three nearby tickets: the
+values 4, 55, and 12 are are not valid for any field. Adding together all of the invalid values
+produces your ticket scanning error rate: 4 + 55 + 12 = 71.
+
+Consider the validity of the nearby tickets you scanned. What is your ticket
+scanning error rate?
+
+