B'Mihai has just learned about the MEX concept and since he liked it so much, he decided to use it right away. Given an array a of n non-negative integers, Mihai wants to create a new array b that is formed in the following way: While a is not empty: But, since Mihai loves big arrays as much as the MEX concept, he wants the new array b to be the lexicographically maximum. So, Mihai asks you to tell him what the maximum array b that can be created by constructing the array optimally is. An array x is lexicographically greater than an array y if in the first position where x and y differ x_i > y_i or if |x| > |y| and y is a prefix of x (where |x| denotes the size of the array x ). The MEX of a set of non-negative integers is the minimal non-negative integer such that it is not in the set. For example, MEX({ {1, 2, 3} }) = 0 and MEX({ {0, 1, 2, 4, 5} }) = 3 . The first line of the input contains a single integer t ( 1 <= t <= 100 ) -- the number of test cases. The description of test cases follows. The first line of each test case contains a single integer n ( 1 <= q n <= q 2 cdot 10^5 ) -- the number of elements in the array a . The second line of each test case contains n non-negative integers a_1, ldots, a_n ( 0 <= q a_i <= q n ), where a_i is the i -th integer from the array a . It is guaranteed that the sum of n over all test cases does not exceed 2 cdot 10^5 . For each test case print m -- the length of the maximum array b Mihai can create, followed by m integers denoting the elements of the array b . In the first test case, the lexicographically maximum array b is obtained by selecting k=5 , resulting in the MEX of the whole array a . It is lexicographically maximum because an array starting with a smaller number than 4'...