ZOJ Problem Set - 1895
For 10 > N > 2 numbers we form N*(N-1)/2 sums by adding every pair of the numbers. Your task is to find the N numbers given the sums.
Each line of input contains N followed by N*(N-1)/2 integer numbers separated by a space.
For each line of input, output one line containing N integers in non-descending order such that the input numbers are pairwise sums of the N numbers. If there is more than one solution, any one will do; if there is no solution, print "Impossible".
3 1269 1160 1663
Source: University of Waterloo Local Contest 2001.09.29