#include<stdio.h>
int n,m,v[256],flip[16][16],smax=0;
void back(int x)
{
    if(x-1==m)
    {
        int sum=0,i,j;
        for(i=0; i<n; i++)
        {
            int s=0;
            for(j=0; j<m; j++)
                if(v[j]-1)
                    s=s-flip[i][j];
                else
                    s=s+flip[i][j];
            if(s<0)
                sum=sum-s;
            else
                sum=sum+s;
            if(sum>smax)
                smax=sum;
        }
    }
    else
    {
        v[x]=0;
        back(x+1);
        v[x]=1;
        back(x+1);
    }
}
int main()
{
    FILE *fin,*fout;
    fin=fopen("flip.in","r");
    fout=fopen("flip.out","w");
    fscanf(fin,"%d%d",&n,&m);
    int i,j;
    for(i=0; i<n; i++)
        for(j=0; j<m; j++)
            fscanf(fin,"%d",&flip[i][j]);
    back(1);
    fprintf(fout,"%d",smax);
    return 0;
}