#include <stdio.h>

#define N 16
#define M 16

int main()
{
  int i, j, k;
  int n, m;
  int sum, line_sum, max = 0;
  int a[N][M];

  freopen("flip.in", "r", stdin);
  freopen("flip.out", "w", stdout);

  scanf("%d%d", &n, &m);

  for(i = 0; i < n; i++)
    for(j = 0; j < m; j++)
      scanf("%d", &a[i][j]);

  for(i = 0; i < (1 << n); i++)
  {
    sum = 0;
    for(j = 0; j < m; j++)
    {
      line_sum = 0;
      for(k = 0; k < n; k++)
        if(i & (1 << k))
          line_sum += a[k][j];
        else
          line_sum -= a[k][j];
      if(line_sum < 0)
        sum -= line_sum;
      else
        sum += line_sum;
    }
    if(sum > max)
      max = sum;
  }

  printf("%d\n", max);

  return 0;
}