#include <stdio.h>
#include <stdlib.h>
int a[17][17];
int s[17];
int maxim;
void cont(int n,int m)
{
    int i,j,sl,st=0;
    for(i=1;i<=m;i++)
    {
        sl=0;
    for(j=1;j<=n;j++)
        sl+=s[j]*a[j][i];
    if(sl<0)
    sl=-sl;
    st+=sl;
    }
    if(st>maxim)
        maxim=st;

}
void back1(int n,int m,int k)
{
    if (k>n)
        cont(n,m);
    else
    {
        s[k]=1;
        back1(n,m,k+1);
        s[k]=-1;
        back1(n,m,k+1);
    }
}
int main()
{
    FILE *pf,*pg;

    pf=fopen("flip.in","r");
    pg=fopen("flip.out","w");

    int m,n;
    fscanf(pf,"%d %d",&n,&m);
    int i,j;
    for (i=1; i<=n; i++)
        for (j=1; j<=m; j++)
            fscanf(pf,"%d ",&a[i][j]);
    back1(n,m,1);
    fprintf(pg,"%d",maxim);


    return 0;
}