#include <stdio.h>

int A[16][16],B[16][16];
int n,m,posib,k,i,j,b,s,sT,sMax;

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


int main(){

  fscanf(f,"%d %d",&n,&m);

  for (i=0; i<n; i++)
    for (j=0; j<m; j++)
      fscanf(f,"%d",&A[i][j]);

  posib = (1<<m) - 1;

  for (k=0; k<=posib; k++) {

    sT = 0;

    for (b=0; b<m; b++)
      if ((k>>b) & 1)
	for (i=0; i<n; i++)
	  B[i][b] = -A[i][b];
      else
	for (i=0; i<n; i++)
	  B[i][b] = A[i][b];

    for (i=0; i<n; i++) {
      s = 0;
      for (j=0; j<m; j++) {
	s += B[i][j];
	if (s<0)
	  s *= -1;
      }
      sT += s;
    }

    if (sT > sMax)
      sMax = sT;

  }

  fprintf(g,"%d",sMax);

  fclose(f);
  fclose(g);

  return 0;
}