#include<cstdio>
#include<math.h>
#define input "flip.in"
#define output "flip.out"

int v[66000];
void desc(int n,int r[66000])
{
  int j,i=0;
  int vt[66000];   
  while(n)
    {
      vt[++i]=n%2;
      n>>=1;
    }
  for(j=1;j<=i;++j) r[j]=vt[i+1-j];
}

int main()
{
  freopen(input,"rt",stdin);
  freopen(output,"wt",stdout);
  int a[20][20];
  int n,m,i,j,s,sum,max,k;
  scanf("%d %d",&n,&m);
  for(i=1;i<=n;++i)
    for(j=1;j<=m;++j)
      scanf("%d",&a[i][j]);
  max=0;
  for(k=int(pow(2,n))-1;k;--k)
  {
    desc(k,v);
    sum=0;
    for(i=1;i<=n;++i)
    {
      a[i][0]=v[i];
      if(a[i][0]==1) for(j=1;j<=m;++j) a[i][j]*=-1;
    }
    for(j=1;j<=m;++j)
    {
      s=0;
      for(i=1;i<=n;++i)
        s+=a[i][j];
      if(s>0) sum+=s;
        else sum-=s;
    }
    if(sum>max) max=sum;
  }
  printf("%d",max); 
  return 0;
}