#include <iostream>
#include <fstream>
using namespace std;

ifstream f("flip.in");
ofstream g("flip.out");

int n,m,v[100][100],solutie=0,a[100],i,j;

int BK(int i)
    {
      if(i<=n)
      {
          a[i]=1;
          BK(i+1);
          a[i]=-1;
          BK(i+1);
      }
      else
      {
          int s1=0,s2=0;
          int k,j;
          for(k=1;k<=m;k++)
          {
              for(j=1;j<=n;j++)
                s1=s1+(v[j][k]*a[j]);
              if(s1<0)
                s1*=-1;
              s2=s2+s1;
              s1=0;
          }
          if(s2>solutie)
            solutie=s2;
      }
    }

int main()
{
    f>>n>>m;
    for(i=1;i<=n;i++)
        for(j=1;j<=m;j++)
            f>>v[i][j];
    BK(1);
    g<<solutie;
}