#include<cstdio>
using namespace std;
int s1,s2,s,a[30][30],i,j,n,m,ss1,ss2,v[100],viz[100],mx,st;
void back(int k)
{int i,j;
st=0;
for(j=1;j<=m;j++)
{s=0;
for(i=1;i<=n;i++)
{if(viz[i]==0)
s=s+a[i][j];
else
s=s-a[i][j];
}
if(s<0)
st=st-s;
else
st=st+s;
}
if(mx<st)
mx=st;
for(i=v[k-1]+1;i<=n;i++)
{v[k]=i;
viz[i]=1;
back(k+1);
viz[i]=0;
}
}
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]);
mx=-10000000;
back(1);
printf("%d",mx);
return 0;
}