Description:
There is a rectangular grid of size $$$n \times m$$$. Each cell has a number written on it; the number on the cell ($$$i, j$$$) is $$$a_{i, j}$$$. Your task is to calculate the number of paths from the upper-left cell ($$$1, 1$$$) to the bottom-right cell ($$$n, m$$$) meeting the following constraints:
- You can move to the right or to the bottom only. Formally, from the cell ($$$i, j$$$) you may move to the cell ($$$i, j + 1$$$) or to the cell ($$$i + 1, j$$$). The target cell can't be outside of the grid.
- The xor of all the numbers on the path from the cell ($$$1, 1$$$) to the cell ($$$n, m$$$) must be equal to $$$k$$$ (xor operation is the bitwise exclusive OR, it is represented as '^' in Java or C++ and "xor" in Pascal).
Find the number of such paths in the given grid.
Input Format:
The first line of the input contains three integers $$$n$$$, $$$m$$$ and $$$k$$$ ($$$1 \le n, m \le 20$$$, $$$0 \le k \le 10^{18}$$$) — the height and the width of the grid, and the number $$$k$$$.
The next $$$n$$$ lines contain $$$m$$$ integers each, the $$$j$$$-th element in the $$$i$$$-th line is $$$a_{i, j}$$$ ($$$0 \le a_{i, j} \le 10^{18}$$$).
Output Format:
Print one integer — the number of paths from ($$$1, 1$$$) to ($$$n, m$$$) with xor sum equal to $$$k$$$.
Note:
All the paths from the first example:
- $$$(1, 1) \rightarrow (2, 1) \rightarrow (3, 1) \rightarrow (3, 2) \rightarrow (3, 3)$$$;
- $$$(1, 1) \rightarrow (2, 1) \rightarrow (2, 2) \rightarrow (2, 3) \rightarrow (3, 3)$$$;
- $$$(1, 1) \rightarrow (1, 2) \rightarrow (2, 2) \rightarrow (3, 2) \rightarrow (3, 3)$$$.
All the paths from the second example:
- $$$(1, 1) \rightarrow (2, 1) \rightarrow (3, 1) \rightarrow (3, 2) \rightarrow (3, 3) \rightarrow (3, 4)$$$;
- $$$(1, 1) \rightarrow (2, 1) \rightarrow (2, 2) \rightarrow (3, 2) \rightarrow (3, 3) \rightarrow (3, 4)$$$;
- $$$(1, 1) \rightarrow (2, 1) \rightarrow (2, 2) \rightarrow (2, 3) \rightarrow (2, 4) \rightarrow (3, 4)$$$;
- $$$(1, 1) \rightarrow (1, 2) \rightarrow (2, 2) \rightarrow (2, 3) \rightarrow (3, 3) \rightarrow (3, 4)$$$;
- $$$(1, 1) \rightarrow (1, 2) \rightarrow (1, 3) \rightarrow (2, 3) \rightarrow (3, 3) \rightarrow (3, 4)$$$.