#include<iostream>
#include<fstream>
#include<Windows.h>
using namespace std;
ifstream in;
ofstream out;

int main() {
	unsigned short N, M;
	long long int a[16][16], s1=0, s2=0, S=0;

	in.open ("flip.in");
	in >> N >> M;
	for (short i = 0; i < N; i++)
	{
		for (short j = 0; j < M; j++)
		{
			in >> a[i][j];
		}
	}
	in.close();


	for (short i = 0; i < N; i++)
	{
		for (short j = 0; j < M; j++)
		{
			s1 += a[i][j];
			s2 -= a[i][j];
		}
		if (s2 > s1)
		{
			for (short j = 0; j < M; j++)
			{
				a[i][j] = -a[i][j];
			}
		}
		s1 = 0;
		s2 = 0;
	}
	for (short j = 0; j < M; j++)
	{
		for (short i = 0; i < N; i++)
		{
			s1 += a[i][j];
			s2 -= a[i][j];
		}
		if (s2 > s1)
		{
			for (short i = 0; i < N; i++)
			{
				a[i][j] = -a[i][j];
			}
		}
		s1 = 0;
		s2 = 0;
	}

	for (short i = 0; i < N; i++)
	{
		for (short j = 0; j < M; j++)
		{
			S += a[i][j];
		}
	}
	
/*	for (short i = 0; i < N; i++)
	{
		for (short j = 0; j < M; j++)
		{
			cout << a[i][j] <<" ";
		}
		cout << "\n";
	}
	cout << "\n" << S <<"\n";
	system("pause"); */
	out.open("flip.out");
	out << S;
	out.close();
}