#include<iostream>
#include<fstream>
using namespace std;
ifstream in("flip.in");
ofstream out("flip.out");
int coloana(int n,int m);
int linie(int n,int m);
int S1[20],S2[20],a[20][20],S;
int main()
{
	int i,j,n,m;
	in>>n>>m;
	for(i=1;i<=n;i++)
	{
		for(j=1;j<=m;j++)
		{
			in >> a[i][j];
		}
	}
	coloana(n,m);
	linie(n,m);
	for(i=1;i<=n;i++)
	{
		for(j=1;j<=m;j++)
		{
			S=S+a[i][j];
		}
		
	}
	out<<S;
}
int coloana(int n,int m)
{
	int i,j;
	for(j=1;j<=m;j++)
	{
		for(i=1;i<=n;i++)
		{
			S1[j]=S1[j]+a[i][j];
			S2[j]=S2[j]+(a[i][j]*-1);
		}
	}
	for(j=1;j<=m;j++)
	{
		for(i=1;i<=n;i++)
		if(S1[j]<S2[j])
		{
			a[i][j]=a[i][j]*-1;
		}
	}
}
int linie(int n,int m)
{
	int i,j;
	for(i=1;i<=n;i++)
	{
		S1[i]=0;
		S2[i]=0;
		for(j=1;j<=m;j++)
		{
			S1[i]=S1[i]+a[i][j];
			S2[i]=S2[i]+(a[i][j]*-1);
		}
	}
	for(i=1;i<=n;i++)
	{
		for(j=1;j<=m;j++)
		if(S1[i]<S2[i])
		{
			a[i][j]=a[i][j]*-1;
		}
	}
}