#include <fstream>
#define abs(a) (a > 0 ? a : a*(-1))
 
using namespace std;
 
int main()
{
int n, m, t[16][16], max=0;
bool a[16];
ifstream in("flip.in");
in >> n >> m;
for(int i = 0; i < n; ++i)
{
for(int j = 0; j < m; ++j)
{
in >> t[i][j];
max += t[i][j];
}
a[i] = 0;
}
in.close();
int t_b = 1<<n;
for (int w = 0; w < t_b; ++w)
{
int sum_t = 0;
for(int j = 0; j < m; ++j)
{
int sum_j = 0;
for(int i = 0; i < n; ++i)
{
if(a[i])
sum_j -= t[i][j];
else
sum_j += t[i][j];
}
sum_t+= abs(sum_j);
}
if (sum_t > max)
max = sum_t;
int f = 0;
.while(a[f])
{
a[f]=0;
++f;
}
a[f]=1;
}
ofstream out("flip.out");
out << max;
out.close();
return 0;
}