DWITE Online Computer Programming Contest, October 2009, Problem 3
You have a continuous sequence of unique numbers, , that you like very much, but your little sister always steals one (and only one), and randomly re-arranges the rest in an attempt to hide the crime. Given numbers, in a random order, find out which number was taken.
The input will contain 5 sets of input. The first line will be an integer , the number of items remaining. Followed by lines of unique integers, from at least to at most .
The output will contain 5 lines, each an integer from the missing set.
Note: the original sorted sequence is . Any of the numbers (including or ) can be taken.
2 1 2 2 2 3 2 1 3
3 1 2
Problem Resource: DWITE