#include <stdio.h>
long m,n,i,j,k,l,o,p;
long a[17][17];
int main()
    {
    freopen("flip.in","r",stdin);
    freopen("flip.out","w",stdout);
    scanf("%ld %ld\n",&m,&n);
    for(i=1;i<=m;i++)
      {
      for(j=1;j<=n;j++)
        {
        scanf("%ld ",&a[i][j]);
        }
      scanf("\n");
      }
    for(k=0;k<=(1<<n)-1;k++)
      {
      o=0;
      for(i=1;i<=m;i++)
        {
        l=0;
        for(j=1;j<=n;j++)
          {
          if(k & (1<<(j-1))) l+=a[i][j];
          else l-=a[i][j];
          }
        if(l>=0)o+=l;
        else o-=l;
        }
      if(o>p)p=o;                  
      }
    printf("%ld",p);
    return 0;
    }