Alice is starting a collection of stickers with the most important figures of the Algorithms and Data Structures world. Each sticker is identified by a number.
In what concerns the continuous evaluation solving exercises grade during the semester, you should submit until 23:59 of December 7th
(this exercise will still be available for submission after that deadline, but without couting towards your grade)
[to understand the context of this problem, you should read the class #08 exercise sheet]
Alice is starting a collection of stickers with the most important figures of the Algorithms and Data Structures world. Each sticker is identified by a number.
Alice keeps track of all the stickers she already has (including repeated stickers) and each time she buys a stickers bag she wants to know how many new stickers she got on that bag. Can you help her in this task?
Given the collection of C stickers Alice already has in her collection and the B stickers that come in the stickers bag she just bought, your task is to compute how many of the B stickers are new, that is, how many were not already in the collection. All stickers are represented by integer numbers.
The first line of the input contains an integer C, representing the number of stickers Alice has in her collection. The second line contains C space separated integers Ci, representing the stickers in the collection (there might exist repeated stickers).
The third line of the input contains an integer B, representing the number of stickers in the bag Alice bought. The fourth line contains B space separated and distinct integers Bi, representing the stickers in the bag.
The output should consist of two lines. The first one should contain the number of stickers in the bag that are new (those that were not already in the collection). The second line should only be printed if there is at least a new sticker and it should contain the list of the new stickers in increasing order, separated by a single space (with no extra spaces at the start or end of the line).
The following limits are guaranteed in all the test cases that will be given to your program:
| 1 ≤ C ≤ 105 | Number of stickers in the collection | |
| 1 ≤ Ci ≤ 109 | Integers representing the stickers in the collection | |
| 1 ≤ B ≤ 105 | Number of stickers in the new bag | |
| 1 ≤ Bi ≤ 109 | Integers representing the stickers in the bag |
| Example Input 1 | Example Output 1 |
7 42 124 34 12 42 24 71 5 112 42 31 34 62 |
3 31 62 112 |
Explanation of Example Input 1:
Alice has an initial collection of 7 stickers: {42, 124, 34, 12, 42, 24, 71}.
The bag she bought has 3 new stickers: 31, 62 and 112 (34, 42 and 62 are repeated and were already on the collection).
| Example Input 2 | Example Output 2 |
6 42 42 17 18 43 56 3 17 56 42 |
0 |
Explanation of Example Input 2:
All stickers on the bag are repeated.