#include<stdio.h>

int main()
{long int n,m,a[20][20],pn,pc,sn=0,sc=0,snt=0,sct=0,st=0,i,j;
freopen("flip.in","r",stdin);
freopen("flip.out","w",stdout);
long min,minn; 
min=2000000000;
minn=2000000000;
scanf("%ld %ld",&n,&m);
for(i=0;i<n;i++)
   {sn=0;
    for(j=0;j<m;j++)
      {scanf("%ld",&a[i][j]);
       sn=sn+a[i][j];
      }
    if(sn<min)
      {min=sn;
       pn=i;
      }
   snt=snt+sn;
   }
int st1=0;
st1=snt;

for(j=0;j<m;j++)
	{sc=0;
    for(i=0;i<n;i++)
       {sc=sc+a[i][j];
       }
    if(sc<minn)
      {minn=sc;
       pc=j;
      }
    sct=sct+sc;
   snt=snt+((-2)*a[pn][j]);
   a[pn][j]=a[pn][j]*(-1);
   }
st=snt;
st1=st1+sct;
for(i=0;i<n;i++)
	{
       st=st+((-2)*a[i][pc]);
       a[i][pc]=a[i][pc]*(-1);
   }
if(st>(st1/2))
     printf("%ld",st);
else
     printf("%ld",st1/2);
return 0;
}