PROGRAMMING:single af
"Single dog" is a Chinese nickname for single people. This topic asks you to find out the guests who are left alone from the large party of tens of thousands of people, so as to give special care.
###Input format:
Enter the first line to give a positive integer n ($$$Le $$50000), which is the logarithm of known couples / partners; Then n lines, each line gives a couple / partner - for convenience, each person corresponds to an ID number, which is 5 digits (from 00000 to 99999), and the IDs are separated by spaces; Then a positive integer m ($$$Le $$10000) is given, which is the total number of people attending the party; The next line gives the ID of the M guests, separated by spaces. The topic guarantees that no one will remarry or step on two boats.
###Output format:
First, the first line outputs the total number of single guests; Then, the second line lists the customers in the order of increasing ID. IDS should be separated by one space, and there should be no extra space at the beginning and end of the line.
###Input example:
```in
three
11111 22222
33333 44444
55555 66666
seven
55555 44444 10000 88888 22222 11111 23333
```
###Output example:
```out
five
10000 23333 44444 55555 88888
```
answer：If there is no answer, please comment
###Input format:
Enter the first line to give a positive integer n ($$$Le $$50000), which is the logarithm of known couples / partners; Then n lines, each line gives a couple / partner - for convenience, each person corresponds to an ID number, which is 5 digits (from 00000 to 99999), and the IDs are separated by spaces; Then a positive integer m ($$$Le $$10000) is given, which is the total number of people attending the party; The next line gives the ID of the M guests, separated by spaces. The topic guarantees that no one will remarry or step on two boats.
###Output format:
First, the first line outputs the total number of single guests; Then, the second line lists the customers in the order of increasing ID. IDS should be separated by one space, and there should be no extra space at the beginning and end of the line.
###Input example:
```in
three
11111 22222
33333 44444
55555 66666
seven
55555 44444 10000 88888 22222 11111 23333
```
###Output example:
```out
five
10000 23333 44444 55555 88888
```
answer：If there is no answer, please comment