#include <fstream>
using namespace std;
ifstream fin("flip.in");
ofstream fout("flip.out");
int n, m, i, j, a[17][17], sum_max, sum;
void citire();
void clear_a();
void com_col();
void com_lin();
int sum_lin_col();
int main()
{
citire();
sum_max = sum_lin_col();
sum = sum_lin_col();
while (sum > sum_max){
sum_max = sum;
sum = sum_lin_col();
}
fout << sum_max;
return 0;
}
void citire()
{
fin >> n >> m;
for (i = 1; i <= n; i++)
{
for (j = 1; j <= m; j++)
{
fin >> a[i][j];
}
}
}
int sum_lin_col()
{
int s=0;
clear_a();
for (i = 1; i <= n; i++)
{
for (j = 1; j <= m; j++)
{
a[0][j] += a[i][j];
a[i][0] += a[i][j];
}
}
com_col();
com_lin();
clear_a();
for (i = 1; i <= n; i++)
{
for (j = 1; j <= m; j++)
{
a[0][j] += a[i][j];
a[i][0] += a[i][j];
}
}
for (i = 1; i <= n; i++) s += a[i][0];
return s;
}
void com_col()
{
for (j = 1; j <= m; j++)
{
if (a[0][j] < 0)
{
for (i = 1; i <= n; i++)
a[i][j] *= -1;
a[0][j] *= -1;
}
}
}
void com_lin()
{
for (i = 1; i <= m; i++)
{
if (a[i][0] < 0)
{
for (j = 1; j <= n; j++)
a[i][j] *= -1;
a[i][0] *= -1;
}
}
}
void clear_a()
{
for (i = 1; i <= n; i++){
a[i][0] = 0;
}
for (i = 1; i <= m; i++){
a[0][i] = 0;
}
}