#include <stdio.h>
int n,m,i,j,v[300],smax=-32000,a[17][17],k;
void cont()
{
     int i,j,s,c;
     s=0;
     for(i=1;i<=n;i++)   
    {   
        c=0;   
        for(j=1;j<=m;j++)   
            c=c+v[j]*a[i][j];   
        if(c>0)   
            s=s+c;   
        else  
            s=s-c;   
    }   
    if(s>smax )   
        smax=s; 
}
void back(int k)
{
     if(k>=m)cont();
     else
     { 
        v[k]=1;   
        back(k+1);   
        v[k]=-1;   
        back(k+1);
     }
}
int main()
{
    freopen("flip.in","r",stdin);
    freopen("flip.out","w",stdout);
    scanf("%d %d\n",&n,&m);
    for(i=1;i<=n;i++)
    {
    for(j=1;j<=m;j++)
    scanf("%d ",&a[i][j]);
    scanf("\n");
    }
    back(0);
    printf("%d",smax);
    fclose(stdin);
    fclose(stdout);
    return 0;
}