#include <stdio.h>
#include <stdlib.h>

int v[17][17],S,sol[17],n,m,i,j,sl;


void back(int k,int s)
{
    if(k==n+m) {if(s>S) S=s; }
    else
    {
        if(k<n)
        {
            sol[k]=1; back(k+1,0);
            sol[k]=-1; back(k+1,0);
        }
        else
        {
            sl=0;

            for(i=0;i<n;i++)
                sl+=(v[i][k-n-1]*sol[i]);


            back(k+1,sl+s);
            back(k+1,-sl+s);
        }
    }
}

int main()
{
    FILE *f=fopen("flip.in","r");
    FILE *fp=fopen("flip.out","w");

    fscanf(f,"%d %d",&n,&m);

    for(i=0;i<n;i++)
        for(j=0;j<m;j++)
        {
            fscanf(f,"%d",&v[i][j]);
        }

    back(0,0);
    fprintf(fp,"%d",S);


    return 0;
}