#include "stdio.h"


int main(void)
{
	FILE *fin, *fout;
	int N, M;
	int a[16][16];
	int line_min, coloana_min, minim;
	int suma;
	int i,j;
	if((fin = fopen("flip.in", "r"))==NULL)
		return -1;
	if((fout = fopen("flip.out", "w"))==NULL)
		return -1;
	fscanf(fin, "%d %d", &N, &M);
	for(i=0; i<N; i++)
		for(j=0; j<M; j++)
			fscanf(fin, "%d", &a[i][j]);
	
	for(i=0; i<N; i++)
	{
		suma=0;
		for(j=0; j<M; j++)
			suma += a[i][j];
		if(i==0)
		{
			minim = suma;
			line_min = 0;
		}
		else if(minim > suma)
		{
			minim = suma;
			line_min = i;
		}
	}
	for(j=0; j<M; j++)
	{
		suma=0;
		for(i=0; i<N; i++)
			suma += a[i][j];
		if(j==0)
		{
			minim = suma;
			coloana_min = 0;
		}
		else if(minim > suma)
		{
			minim = suma;
			coloana_min = j;
		}
	}
	for(i=0; i<N; i++)
		a[i][coloana_min] *= -1;
	for(j=0; j<M; j++)
		a[line_min][j] *= -1;
	suma = 0;
	for(i=0; i<N; i++)
		for(j=0; j<M; j++)
			suma += a[i][j];
	fprintf(fout, "%d\n", suma);
	fclose(fin);
	fclose(fout);
	return 0;
}