#include<fstream>
using namespace std;

ifstream fin("flip.in");
ofstream fout("flip.out");

int n, m, i, j, sum, s, summax;
int a[17][17], v[17];

void readf()
{
     fin >> n >> m;
     for( i=1; i<=n; i++ )
     for( j=1; j<=n; j++ )
     fin >> a[i][j];
     fin.close();
}

void sum_it()
{    
     s = 0;
     for( j=1; j<=m; i++ )
     {
              sum = 0;
              for( i=1; i<=n; i++ )
              sum = sum + a[i][j] * v[j];
     if(sum<0) sum = sum - sum - sum;
     s = s + sum;
     }
     if( s > summax ) summax = sum;
}

void generate(int k)
{
     if( k == n + 1 ) sum_it();
     else
     {
         for(i=-1;i<=1;i = i+2) v[k]=i, generate(k+1);
         }
}

void showf()
{
     fout << summax;
     fout.close();
}

int main()
{   
    readf();
    generate(1);
    showf();
    return 0;
}