P8184 [CF2011H] Strange Matrix
普及
题目描述

You are given a matrix $a$ of size $n \times m$, consisting of integers from $0$ to $31$ inclusive.

Let's call the matrix strange if for every two distinct rows $i$ and $j$, both of the following conditions hold:

  • for every set of $k$ indices $(x_1, x_2, \dots, x_k)$, where $1 \le x_1 < x_2 < \cdots < x_k \le m$, the equality $a_{i, x_1} \mathbin{\&} a_{j, x_1} \mathbin{\&} a_{i, x_2} \mathbin{\&} a_{j, x_2} \mathbin{\&} \cdots \mathbin{\&} a_{i, x_k} \mathbin{\&} a_{j, x_k} = 0$ holds (where $\mathbin{\&}$ — bitwise AND of two numbers);
  • for every set of $k$ indices $(x_1, x_2, \dots, x_k)$, where $1 \le x_1 < x_2 < \cdots < x_k \le m$, the equality $a_{i, x_1} \mathbin{|} a_{j, x_1} \mathbin{|} a_{i, x_2} \mathbin{|} a_{j, x_2} \mathbin{|} \cdots \mathbin{|} a_{i, x_k} \mathbin{|} a_{j, x_k} = 31$ holds (where $\mathbin{|}$ — bitwise OR of two numbers).

You can perform the following operation any number of times: take any row of the matrix and a number $y$ from $0$ to $31$ inclusive; then apply the bitwise XOR with the number $y$ to all elements of the selected row. The cost of such an operation is equal to $y$.

Your task is to calculate the minimum cost to make the matrix strange, or report that it is impossible.

Input

The first line contains one integer $t$ ($1 \le t \le 100$) — the number of test cases.

The first line of each test case contains three integers $n$, $m$, and $k$ ($1 \le n, m \le 50$; $1 \le k \le m$).

Next, there are $n$ lines, the $i$-th of which contains $m$ integers $a_{i, 1}, a_{i, 2}, \dots, a_{i, m}$ ($0 \le a_{i, j} \le 31$).

Output

For each test case, output one integer — the minimum cost to make the matrix strange, or -1 if it is impossible to make the matrix strange.

输入格式

见题面 Input 部分

输出格式

见题面 Output 部分

样例输入
3 2 3 1 0 1 0 1 0 1 3 2 2 0 1 2 3 4 5 5 5 5 0 5 17 4 22 8 5 16 21 9 7 25 31 30 8 0 0 5 15 13 1 2 3 4 5
样例输出
30 -1 24