Consider a grid of size n x n where each cell contains a number. Let’s call a grid stable if we can rearrange the numbers of each row so that every column of the resulting grid has no repeated values. Mathematically, say, we have a grid G of size n × n. We would like to permute the elements of each row Gi (1 ≤ i ≤ n) so that the resulting grid has the following property: For every column j, the values Gi,j are all distinct for (1 ≤ i ≤ n). As an example, consider a grid G of size 4 × 4 as shown below 2113 3126 2 6 10 3 9876 We can permute each row to get G′ as shown below 2113 1362 6 2 3 10 9876 In G′, there are no repeated values in any column. So, the given grid is stable. In this problem, you will be given a grid of size n × n and you have to determine whether it is stable or not. Input Input starts with an integer T (≤ 500), denoting the number of test cases. Each case starts with a line containing the value of n (0 < n < 100). The next n lines contain n integers each. The j-th integer of the i-th line represent the value of Gi,j. Consecutive integers in each line are separated with space characters. All the integers in the grid are non-negative with magnitude not greater than 100. Output For each case, output the case number first. If the given grid is stable, output ‘yes’ otherwise output ‘no’. Look at the samples for exact format. Sample Input 3 4 2113 3126 2 6 10 3 9876 3
2/2 112 111 222 3 123 231 312 Sample Output Case 1: yes Case 2: no Case 3: yes