#include<fstream.h>
int n,m,i,j,sum,max,a[20][20],b[50];
ifstream f("flip.in");
ofstream g("flip.out");
int main(){
f>>n>>m;
for(i=1;i<=n;i++)
for(j=1;j<=m;j++)
	{f>>a[i][j];
	max+=a[i][j];
	}
for(;b[n+m]==0;b[1]++)
{for(j=1;j<=n+m;j++)
	if(b[j]==2)
		{b[j+1]++;
		b[j]=0;}
sum=0;
for(i=1;i<=n;i++)
for(j=1;j<=m;j++)
	{if(b[i]!=b[n+j])
		sum-=a[i][j];
	else
		sum+=a[i][j];
	}
if(sum>max)
	max=sum;
}
g<<max;
f.close();
g.close();
return 0;}