#include <stdio.h>

int a[16][16],m,n;
int max =0;

FILE *f=fopen("flip.in","r");
FILE *g=fopen("flip.out","w");

void com_linie(int l) {
    for(int i = 0; i < m; ++i) {
        a[l][i] *= -1;
    }
}

void suma()
{   int s=0, sc=0;
    for (int i=0;i<m;i++)
    {   sc=0;
        for (int j=0;j<n;j++)
            sc+= a[j][i];
        if(sc<0) sc=-sc;
        s+=sc;}
    if (s > max) max = s;
}

void back(int l)
{ if (l == n) suma();
  else { back(l + 1);
         com_linie(l);
         back(l + 1);
          }
   }

int main()
{   fscanf(f,"%d %d",&n,&m);
    for(int i=0;i<n;i++)
        for(int j=0;j<m;j++)
            fscanf(f,"%d",&a[i][j]);
    back(0);
    fprintf(g,"%d", max);
    return 0;
}