B'Every December, VK traditionally holds an event for its employees named "Secret Santa". Here 's how it happens. n employees numbered from 1 to n take part in the event. Each employee i is assigned a different employee b_i , to which employee i has to make a new year gift. Each employee is assigned to exactly one other employee, and nobody is assigned to themselves (but two employees may be assigned to each other). Formally, all b_i must be distinct integers between 1 and n , and for any i , b_i ne i must hold. The assignment is usually generated randomly. This year, as an experiment, all event participants have been asked who they wish to make a gift to. Each employee i has said that they wish to make a gift to employee a_i . Find a valid assignment b that maximizes the number of fulfilled wishes of the employees. Each test contains multiple test cases. The first line contains the number of test cases t ( 1 <= t <= 10^5 ). Description of the test cases follows. Each test case consists of two lines. The first line contains a single integer n ( 2 <= n <= 2 cdot 10^5 ) -- the number of participants of the event. The second line contains n integers a_1, a_2, ldots, a_n ( 1 <= a_i <= n ; a_i ne i ) -- wishes of the employees in order from 1 to n . It is guaranteed that the sum of n over all test cases does not exceed 2 cdot 10^5 . For each test case, print two lines. In the first line, print a single integer k ( 0 <= k <= n ) -- the number of fulfilled wishes in your assignment. In the second line, print n distinct integers b_1, b_2, ldots, b_n ( 1 <= b_i <= n ; b_i ne i ) -- the numbers of employees assigned to employees 1, 2, ldots, n . k must be equal to the number of values of i such that a_i = b_i , and must be as large as possible. If '...