#include<fstream.h>
#include<values.h>
int main()
{
int sn[101],sm[101],n,m,i,j,v[101][18],minn=32756,minm=32756,s=0,kn,km;
ifstream in("flip.in");
ofstream out("flip.out");
in>>n>>m;
memset(sn,0,101);
memset(sm,0,101);
for(i=1;i<=n;i++)
	for(j=1;j<=m;j++)
		in>>v[i][j];
for(i=1;i<=n;i++)
	{
	for(j=1;j<=m;j++)
		sn[i]=sn[i]+v[i][j];
	if(sn[i]<minn)
		{
		minn=sn[i];
		kn=i;
		}
	}
for(j=1;j<=m;j++)
	{
	for(i=1;i<=n;i++)
		sm[j]=sm[j]+v[i][j];
	if(sm[j]<minm)
		{
		minm=sm[j];
		km=j;
		}
	}
for(j=1;j<=m;j++)
	v[kn][j]=v[kn][j]*(-1);
for(i=1;i<=n;i++)
	v[i][km]=v[i][km]*(-1);
for(i=1;i<=n;i++)
	for(j=1;j<=m;j++)
		s=s+v[i][j];
out<<s;
in.close();
out.close();
return 0;
}