Problem1971--Binary Table

1971: Binary Table

Time Limit: 2 Sec  Memory Limit: 256 MB
Submit: 0  Solved: 0
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Description

time limit per test
6 seconds
memory limit per test
256 megabytes
input
standard input
output
standard output

You are given a table consisting of n rows and m columns. Each cell of the table contains either 0 or 1. In one move, you are allowed to pick any row or any column and invert all values, that is, replace 0 by 1 and vice versa.

What is the minimum number of cells with value 1 you can get after applying some number of operations?

Input

The first line of the input contains two integers n and m (1≤n≤20, 1≤m≤100000)− the number of rows and the number of columns, respectively.

Then n lines follows with the descriptions of the rows. Each line has length m and contains only digits '0' and '1'.

Output

Output a single integer− the minimum possible number of ones you can get after applying some sequence of operations.

Example
Input
3 4
0110
1010
0111
Output
2

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