#include <fstream>
#include <iostream>
 
using namespace std;
ifstream f("flip.in");
ofstream g("flip.out");
int N, M, ans, v[17][17], w[17][17], m;
 
int main()
{
  f >> N >> M;
  for(int i = 1; i <= N; ++i)
  {
    for(int j = 1; j <= M; ++j)
    {
      f >> v[i][j];
    }
  }

  for(int i = 0; i <= (1 << N); ++i)
  {
    int j = N, k = i;
      while(j != 0)
      {
        if(k & 1)
        {
          for(int l = 1; l <= M; ++l)
          {
            w[j][l] = -v[j][l];
          }
        }
        else
        {
          for(int l = 1; l <= M; ++l)
          {
            w[j][l] = v[j][l];
          }
        }
        k = (k >> 1);
        j--;
      }
      int sum = 0;
      for(int j = 1; j <= M; ++j)
      {
        int sump = 0;
        for(int l = 1; l <= N; ++l)
        {
            sump += w[l][j]; 
        }
        sump = max(sump, -sump);
        sum += sump;
      }
     m = max(m, sum);
  }
  g << m;
  
}