#include <stdio.h>
#include <string.h>

#define maxn 17

int n,m;
int st[maxn],fol[1];
int a[maxn][maxn];
long max;

void readdata()
{
    FILE *f = fopen("flip.in","rt");
    fscanf(f,"%d%d",&n,&m);
    for (int i=1;i<=n;i++)
    {
        for (int j=1;j<=m;j++)
        {
            fscanf(f,"%d",&a[i][j]);
        }
    }
    fclose(f);
}

void sol()
{
    int c[maxn][maxn];
    int i,j;
    for (i=1;i<=n;i++)
    {
        if (st[i])
        {
            for (j=1;j<=m;j++)
            {
                c[i][j] = -a[i][j];
            }
        }
            else
        {
            for (j=1;j<=m;j++)
            {
                c[i][j] = a[i][j];
            }
        }
    }
    long s,t=0;
    for (j=1;j<=m;j++)
    {
        s=0;
        for (i=1;i<=n;i++)
        {
            s+=c[i][j];
        }
        if (s<0)
        {
            t+=-s;
        }
            else t+=s;
    }
    if (t>max) max=t;
}

void back(int k)
{
    if (k>n)
    {
        sol();
    }
        else
    {
        for (int i=0;i<=1;i++)
        {
            if (fol[i]<=n)
            {
                fol[i]++;
                st[k]=i;
                back(k+1);
                fol[i]--;
            }
        }
    }
}

void solve()
{
   max = 0;
    memset(fol,0,sizeof(fol));
    back(1);
}

void writedata()
{
    FILE *f = fopen("flip.out","wt");
    fprintf(f,"%ld",max);
    fclose(f);
}

int main()
{
    readdata();
    solve();
    writedata();
    return 0;
}