#include<cstdio>
int n,m,i,j,k,st[17],e,a[17][17],l[17],c[17],c1[17],p,s;
int main()
{freopen("flip.in","r",stdin);
freopen("flip.out","w",stdout);
scanf("%d%d",&n,&m);
for(i=1;i<=n;i++)
for(j=1;j<=m;j++)
     scanf("%d",&a[i][j]),l[i]+=a[i][j],c[j]+=a[i][j];
for(i=1;i<=n;i++)
     {k=1,st[k]=0;
     while(k>0)
            {st[k]++;
            if(st[k]<=n)
                    if(k==i)
                            {s=0;
                            for(j=1;j<=m;j++)
                                    {c1[j]=c[j];
                                    for(e=1;e<=i;e++)
                                            c1[j]=c1[j]-2*a[st[e]][j];
                                    if(c1[j]<0)
                                            c1[j]=-c1[j];
                                    s+=c1[j];}
                            if(s>p)
                                    p=s;}
                    else
                            k++,st[k]=st[k-1];
            else
                    k--;}}
printf("%d",p);
return 0;}