CF908E New Year and Entity Enumeration
Description
You are given an integer $ m $ .
Let $ M=2^{m}-1 $ .
You are also given a set of $ n $ integers denoted as the set $ T $ . The integers will be provided in base 2 as $ n $ binary strings of length $ m $ .
A set of integers $ S $ is called "good" if the following hold.
1. If , then .
2. If , then 
3. 
4. All elements of $ S $ are less than or equal to $ M $ .
Here,  and  refer to the bitwise XOR and bitwise AND operators, respectively.
Count the number of good sets $ S $ , modulo $ 10^{9}+7 $ .
Input Format
The first line will contain two integers $ m $ and $ n $ ( $ 1
Output Format
Print a single integer, the number of good sets modulo $ 10^{9}+7 $ .
Explanation/Hint
An example of a valid set $ S $ is {00000, 00101, 00010, 00111, 11000, 11010, 11101, 11111}.