zk has n numbers $a_1,a_2,...,a_n$. For each (i,j) satisfying 1≤i<j≤n, zk generates a new number $(a_i+a_j)$. These new numbers could make up a new sequence $b_1，b_2, ... ,b_{n(n-1)/2}$. LsF wants to make some trouble. While zk is sleeping, Lsf mixed up sequence a and b with random order so that zk can't figure out which numbers were in a or b. "I'm angry!", says zk. Can you help zk find out which n numbers were originally in a?
输入解释
Multiple test cases(not exceed 10). For each test case: $\bullet$The first line is an integer m(0≤m≤125250), indicating the total length of a and b. It's guaranteed m can be formed as n(n+1)/2. $\bullet$The second line contains m numbers, indicating the mixed sequence of a and b. Each $a_i$ is in [1,10^9]
输出解释
For each test case, output two lines. The first line is an integer n, indicating the length of sequence a; The second line should contain n space-seprated integers $a_1,a_2,...,a_n(a_1≤a_2≤...≤a_n)$. These are numbers in sequence a. It's guaranteed that there is only one solution for each case.