#include <iostream>
#include <fstream>
using namespace std;
fstream f("flip.in",ios::in);
fstream g("flip.out",ios::out);
int i,j,n,m,a[16][16],s;
int citire(int &n,int &m,int a[][16])
{
f>>n>>m;
   for(i=1;i<=n;i++)
    for(j=1;j<=m;j++)
   f>>a[i][j];
   return 0;}
int suma(int n,int m,int a[][16])
{int s=0;
    for(i=1;i<=n;i++)
        for(j=1;j<=m;j++)
        s=s+a[i][j];
    return s;
}
int verificare(int n,int m,int a[][16])
{int s1,s2=0;
for(i=1;i<=n;i++)
    {s1=0; s2=0;
    for(j=1;j<=m;j++)
    s1=s1+a[i][j];
    //flip
        for(j=1;j<=m;j++)
        {a[i][j]=-a[i][j];
        s2=s2+a[i][j];}
    if(s2<s1)
        for(j=1;j<=m;j++)
        a[i][j]=-a[i][j];}
//2
for(j=1;j<=m;j++)
        {s1=0; s2=0;
        for(i=1;i<=n;i++)
            s1=s1+a[i][j];
    //flip
        for(i=1;i<=n;i++)
        {a[i][j]=-a[i][j];
        s2=s2+a[i][j];}
    if(s2<s1)
     for(i=1;i<=n;i++)
    a[i][j]=-a[i][j];
            }

return 0;}
int main()
{
    citire(n,m,a);
    verificare(n,m,a);
    g<<suma(n,m,a);
    g.close();
    return 0;
}