#include<fstream>
using namespace std;
ifstream f("flip.in");
ofstream g("flip.out");

int a[20][20],m,n,s;long i,j,s1,r,t;

int main()
{f>>n>>m;
for (i=0;i<n;i++)
for (j=0;j<m;j++) f>>a[i][j];

for (r=0;r<(1<<m);r++)
{s1=0;
    for (i=0;i<n;i++)
    {    for (t=j=0;j<m;j++) if (r&(1<<j)) t+=-a[i][j];
                             else t+=a[i][j];
    s1+=max(t,-t);    
    }

 if (s1>s) s=s1;
}
g<<s;
}